diff --git a/src/BRSRC13/CMakeLists.txt b/src/BRSRC13/CMakeLists.txt
index a8895ec7..dabfd9ee 100644
--- a/src/BRSRC13/CMakeLists.txt
+++ b/src/BRSRC13/CMakeLists.txt
@@ -15,12 +15,15 @@ target_link_libraries(brender PRIVATE harness compile_with_werror)
 if(NOT MSVC)
     target_compile_options(brender PRIVATE
         -Wall
+    )
+    add_compile_flags_if_supported(brender
         -Wno-return-type
         -Wno-unused-variable
         -Wno-unused-parameter
         -Wno-sign-compare
         -Wno-int-conversion  #todo!
         -Wno-strict-aliasing
+        -Wstrict-prototypes
     )
     
     target_link_libraries(brender PUBLIC m)
diff --git a/src/DETHRACE/CMakeLists.txt b/src/DETHRACE/CMakeLists.txt
index d75e78d8..db255787 100644
--- a/src/DETHRACE/CMakeLists.txt
+++ b/src/DETHRACE/CMakeLists.txt
@@ -32,6 +32,7 @@ else()
         -Wno-error=format-overflow
         -Wno-error=unused-but-set-variable  # (SelectRaceDraw::test2), etc
         -Wno-format-overflow
+        -Wstrict-prototypes
     )
 endif()
 if(DETHRACE_FIX_BUGS)
diff --git a/src/DETHRACE/common/demo.c b/src/DETHRACE/common/demo.c
index 2cfbc2ea..d3da987c 100644
--- a/src/DETHRACE/common/demo.c
+++ b/src/DETHRACE/common/demo.c
@@ -67,7 +67,7 @@ void DoDemo() {
         }
     }
     S3StopSound(song_tag);
-    S3StopAllOutletSounds(gEffects_outlet);
+    S3StopOutletSound(gEffects_outlet);
     S3StopAllOutletSounds();
     fclose(f);
     FadePaletteDown();
diff --git a/src/DETHRACE/common/flicplay.c b/src/DETHRACE/common/flicplay.c
index a7081a4e..5fcb525f 100644
--- a/src/DETHRACE/common/flicplay.c
+++ b/src/DETHRACE/common/flicplay.c
@@ -1440,7 +1440,7 @@ int PlayNextFlicFrame(tFlic_descriptor* pFlic_info) {
 }
 
 // IDA: int __usercall PlayFlic@<EAX>(int pIndex@<EAX>, tU32 pSize@<EDX>, tS8 *pData_ptr@<EBX>, br_pixelmap *pDest_pixelmap@<ECX>, int pX_offset, int pY_offset, void (*DoPerFrame)(), int pInterruptable, int pFrame_rate)
-int PlayFlic(int pIndex, tU32 pSize, tS8* pData_ptr, br_pixelmap* pDest_pixelmap, int pX_offset, int pY_offset, void (*DoPerFrame)(), int pInterruptable, int pFrame_rate) {
+int PlayFlic(int pIndex, tU32 pSize, tS8* pData_ptr, br_pixelmap* pDest_pixelmap, int pX_offset, int pY_offset, void (*DoPerFrame)(void), int pInterruptable, int pFrame_rate) {
     int finished_playing;
     tFlic_descriptor the_flic;
     tU32 last_frame;
diff --git a/src/DETHRACE/common/sound.c b/src/DETHRACE/common/sound.c
index 19ce6d83..eb48ac91 100644
--- a/src/DETHRACE/common/sound.c
+++ b/src/DETHRACE/common/sound.c
@@ -13,6 +13,7 @@
 #include "piping.h"
 #include "replay.h"
 #include "s3/s3.h"
+#include "s3/s3_brender.h"
 #include "utility.h"
 
 int gSound_detail_level;
diff --git a/src/DETHRACE/pc-dos/dosnet.c b/src/DETHRACE/pc-dos/dosnet.c
index 6ec8654b..e33e48ae 100644
--- a/src/DETHRACE/pc-dos/dosnet.c
+++ b/src/DETHRACE/pc-dos/dosnet.c
@@ -36,6 +36,32 @@ unsigned short gECB_offset;
 tU16 gListen_selector;
 tU16 gSend_selector;
 
+/*static*/ void ClearupPDNetworkStuff(void);
+/*static*/ void MATTMessageCheck(char* pFunction_name, tNet_message* pMessage, int pAlleged_size);
+/*static*/ int GetProfileText(char* pDest, int pDest_len, char* pFname, char* pKeyname);
+/*static*/ int GetSocketNumberFromProfileFile(void);
+/*static*/ tU32 EthernetAddressToU32(_IPX_LOCAL_TARGET* pAddr_ipx);
+/*static*/ void NetNowIPXLocalTarget2String(char* pString, _IPX_LOCAL_TARGET* pSock_addr_ipx);
+/*static*/ int GetMessageTypeFromMessage(char* pMessage_str)  ;
+/*static*/ int SameEthernetAddress(_IPX_LOCAL_TARGET* pAddr_ipx1, _IPX_LOCAL_TARGET* pAddr_ipx2);
+/*static*/ _IPX_LOCAL_TARGET* GetIPXAddrFromPlayerID(tPlayer_ID pPlayer_id);
+/*static*/ void MakeMessageToSend(int pMessage_type);
+/*static*/ int ReceiveHostResponses(void);
+/*static*/ int BroadcastMessage(void);
+/*static*/ int hmiIPXCloseSocket(W32 wSocket);
+/*static*/ void hmiIPXListenForPacket(_IPX_ECB* pECB_ptr, tU32 pOffset);
+/*static*/ int hmiIPXPostListen(_IPX_ECB* pECB_ptr, tU32 pOffset);
+/*static*/ int hmiIPXGetData(char* pData, tU32 wDSize);
+/*static*/ void hmiIPXSendPacket(_IPX_ECB* sECB, _IPX_ECB** pPacket, char* pHeader, W32 wSize);
+/*static*/ int hmiIPXSendDataDirect(char* pHeader, W32 wHSize, char* pData, W32 wDSize, _NETNOW_NODE_ADDR* sNode);
+/*static*/ void hmiIPXGetInternetworkAddr(_IPX_INTERNET_ADDR* sInterworkAddr);
+/*static*/ void hmiIPXGetLocalTarget(_IPX_LOCAL_TARGET* sNetworkAddr);
+/*static*/ int AllocateRealMem(W32 wSize, char** pPtr, W32* pSegment, tU16* pSelector);
+/*static*/ int FreeRealMem(tU16 pSelector);
+/*static*/ int hmiIPXInstalled(void);
+/*static*/ void GetLargestPacketSizeOoErBetterInsertLinfordChristieJokeHere(void);
+/*static*/ void GetIPXToStickItsEarToTheGround(void);
+
 // IDA: void __cdecl ClearupPDNetworkStuff()
 void ClearupPDNetworkStuff() {
     LOG_TRACE("()");
diff --git a/src/DETHRACE/pc-win95/ssdx.h b/src/DETHRACE/pc-win95/ssdx.h
index fb304f24..f0e566b5 100644
--- a/src/DETHRACE/pc-win95/ssdx.h
+++ b/src/DETHRACE/pc-win95/ssdx.h
@@ -8,8 +8,8 @@
 
 int SSDXStart(void* hWnd, int windowed, int flags);
 int SSDXInitDirectDraw(int width, int height, int* row_bytes);
-void SSDXRelease();
-void SSDXLockAttachedSurface();
+void SSDXRelease(void);
+void SSDXLockAttachedSurface(void);
 void SSDXGetWindowRect(void* hWnd);
 void SSDXHandleError(int error);
 
diff --git a/src/DETHRACE/pc-win95/win95sys.c b/src/DETHRACE/pc-win95/win95sys.c
index 42153d07..d57278d2 100644
--- a/src/DETHRACE/pc-win95/win95sys.c
+++ b/src/DETHRACE/pc-win95/win95sys.c
@@ -77,17 +77,34 @@ int gNetwork_profile_file_exists = 0;
 
 char* _unittest_last_fatal_error;
 
-void Win32InitScreen();
-void Win32PumpMessages();
-void Win32ReleaseInputDevice();
-void Win32FatalError(char* pStr_1, char* pStr_2);
-void Win32BRenderWarningFunc(char* msg);
-void Win32BRenderFailureFunc(char* msg);
-void Win32AllocateActionReplayBuffer();
-void Win32CreateWindow();
-void Win32InitInputDevice();
+int original_main(int pArgc, char** pArgv);
 
-extern void QuitGame();
+/*static*/ void KeyboardHandler(void);
+/*static*/ int KeyDown(tU8 pScan_code);
+/*static*/ void KeyTranslation(tU8 pKey_index, tU8 pScan_code_1, tU8 pScan_code_2);
+/*static*/ void KeyBegin(void);
+/*static*/ void KeyEnd(void);
+/*static*/ int KeyDown22(int pKey_index);
+static void Win32ReleaseInputDevice(void);
+static void Win32PumpMessages(void);
+static HARNESS_NORETURN void Win32FatalError(char* pStr_1, char* pStr_2);
+static void Win32CreateWindow(void);
+static void Win32InitScreen(void);
+/*static*/ void Copy8BitTo16BitPixelmap(br_pixelmap* pDst, br_pixelmap* pSrc, br_pixelmap* pPalette);
+/*static*/ void SwapBackScreen(void);
+/*static*/ void ReallyCopyBackScreen(int pRendering_area_only, int pClear_top_and_bottom);
+/*static*/ void CopyBackScreen(int pRendering_area_only);
+static void Win32SetPaletteEntries(uint8_t* entries, int pFirst_colour, int pCount);
+static void Win32InitInputDevice(void);
+static  void Win32AllocateActionReplayBuffer(void);
+static void Usage(char* pProgpath);
+/*static*/ int OurGetChar(void);
+/*static*/ int InitJoysticks(void);
+/*static*/ tU32 ReadJoystickAxis(int pBit);
+static void Win32BRenderWarningFunc(char* msg);
+static void Win32BRenderFailureFunc(char* msg);
+
+extern void QuitGame(void);
 
 void KeyboardHandler() {
     tU8 scan_code;
diff --git a/src/DETHRACE/pd/sys.h b/src/DETHRACE/pd/sys.h
index d9ddead3..ad4f79fb 100644
--- a/src/DETHRACE/pd/sys.h
+++ b/src/DETHRACE/pd/sys.h
@@ -68,7 +68,7 @@ void PDSetKeyArray(int* pKeys, int pMark);
 
 int PDGetASCIIFromKey(int pKey);
 
-void PDFatalError(char* pThe_str);
+HARNESS_NORETURN void PDFatalError(char* pThe_str);
 
 void PDNonFatalError(char* pThe_str);
 
diff --git a/src/S3/3d.h b/src/S3/3d.h
index f010b710..b1225316 100644
--- a/src/S3/3d.h
+++ b/src/S3/3d.h
@@ -6,8 +6,8 @@
 
 void S3Set3DSoundEnvironment(float a1, float a2, float a3);
 
-void S3UpdateListenerVectors();
-void S3ServiceSoundSources();
+void S3UpdateListenerVectors(void);
+void S3ServiceSoundSources(void);
 int S3UpdateSpatialSound(tS3_channel* chan);
 int S3BindAmbientSoundToOutlet(tS3_outlet* pOutlet, int pSound, tS3_sound_source* source, float pMax_distance, int pPeriod, int pRepeats, int pVolume, int pPitch, int pSpeed);
 void S3UpdateSoundSource(tS3_outlet* outlet, tS3_sound_tag tag, tS3_sound_source* src, float pMax_distance_squared, int pPeriod, tS3_repeats pAmbient_repeats, tS3_volume pVolume, int pPitch, tS3_speed pSpeed);
diff --git a/src/S3/CMakeLists.txt b/src/S3/CMakeLists.txt
index 46e5523a..2771378c 100644
--- a/src/S3/CMakeLists.txt
+++ b/src/S3/CMakeLists.txt
@@ -2,7 +2,7 @@ add_library(s3 STATIC)
 
 target_include_directories(s3 
     PUBLIC
-        include
+        "${CMAKE_CURRENT_SOURCE_DIR}/include"
     PRIVATE
         ${CMAKE_SOURCE_DIR}      
 )
@@ -11,6 +11,9 @@ target_link_libraries(s3 PRIVATE brender SDL2::SDL2 harness miniaudio compile_wi
 
 if(NOT MSVC)
     target_link_libraries(s3 PUBLIC pthread m)
+    add_compile_flags_if_supported(s3
+        -Wstrict-prototypes
+    )
 else()
     target_compile_definitions(s3 PRIVATE -D_CRT_SECURE_NO_WARNINGS)
     target_compile_options(s3 PRIVATE
@@ -45,5 +48,4 @@ target_sources(s3 PRIVATE
     s3music.h
     s3sound.c
     s3sound.h
-    
 )
diff --git a/src/S3/audio.c b/src/S3/audio.c
index 7decdc06..d7696e89 100644
--- a/src/S3/audio.c
+++ b/src/S3/audio.c
@@ -1,6 +1,7 @@
 #include "audio.h"
 #include "resource.h"
 
+#include "s3/s3.h"
 #include "3d.h"
 #include "harness/config.h"
 #include "harness/os.h"
@@ -16,7 +17,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-extern int PDGetTotalTime();
+extern int PDGetTotalTime(void);
 
 int gS3_enabled;
 int gS3_noutlets;
diff --git a/src/S3/audio.h b/src/S3/audio.h
index e875210d..a231e4f9 100644
--- a/src/S3/audio.h
+++ b/src/S3/audio.h
@@ -13,26 +13,26 @@ extern int gS3_inside_cockpit;
 
 int S3Init(char* path, int low_memory_mode);
 
-void S3Enable();
-void S3Disable();
+void S3Enable(void);
+void S3Disable(void);
 
-int S3OpenOutputDevices();
-int S3OpenSampleDevice();
-int S3OpenCDADevice();
+int S3OpenOutputDevices(void);
+int S3OpenSampleDevice(void);
+int S3OpenCDADevice(void);
 
-int S3OpenSampleDevice();
-void S3CloseDevices();
+int S3OpenSampleDevice(void);
+void S3CloseDevices(void);
 tS3_outlet* S3CreateOutlet(int unk1, int pChannel_count);
 int S3CreateOutletChannels(tS3_outlet* outlet, int pChannel_count);
 void S3DisposeOutlet(tS3_outlet* outlet);
 int S3UnbindChannels(tS3_outlet* outlet);
-void S3DisposeUnboundChannels();
+void S3DisposeUnboundChannels(void);
 tS3_channel* S3AllocateChannel(tS3_outlet* outlet, int priority);
 int S3StopChannel(tS3_channel* chan);
 
 void S3DisposeOutlet(tS3_outlet* outlet);
 int S3StopOutletSound(tS3_outlet* pOutlet);
-void S3StopAllOutletSounds();
+void S3StopAllOutletSounds(void);
 
 int S3DisposeDescriptor(tS3_sound_id id);
 
@@ -46,10 +46,10 @@ void S3SoundBankReaderAdvance(tS3_soundbank_read_ctx* buffer, int bytes_read);
 int S3SoundBankReaderReadFilename(char** filename, tS3_soundbank_read_ctx* ctx, const char* dir_name);
 int S3SoundBankReadEntry(tS3_soundbank_read_ctx* ctx, char* dir_name, int low_memory_mode);
 
-tS3_descriptor* S3AllocateDescriptor();
+tS3_descriptor* S3AllocateDescriptor(void);
 tS3_descriptor* S3GetDescriptorByID(tS3_sound_id id);
 
-char* S3GetCurrentDir();
+char* S3GetCurrentDir(void);
 
 void S3CalculateRandomizedFields(tS3_channel* chan, tS3_descriptor* desc);
 int S3IRandomBetween(int pMin, int pMax, int pDefault);
@@ -62,7 +62,7 @@ int S3SetOutletVolume(tS3_outlet* pOutlet, tS3_volume pVolume);
 tS3_channel* S3GetChannelForTag(tS3_sound_tag tag);
 int S3SetTagVolume(tS3_sound_tag pTag, tS3_volume pVolume);
 
-void S3ServiceOutlets();
+void S3ServiceOutlets(void);
 int S3ServiceChannel(tS3_channel* chan);
 void S3Service(int inside_cockpit, int unk1);
 
diff --git a/src/S3/include/s3/s3.h b/src/S3/include/s3/s3.h
index 8ad56cf8..95e649d7 100644
--- a/src/S3/include/s3/s3.h
+++ b/src/S3/include/s3/s3.h
@@ -4,7 +4,8 @@
 // External typedefs
 
 typedef float tF32;
-typedef char* tS3_sound_source_ptr;
+typedef struct tS3_sound_source tS3_sound_source;
+typedef tS3_sound_source *tS3_sound_source_ptr;
 typedef int tS3_sound_tag;
 typedef int tS3_sound_id;
 typedef int tS3_type;
@@ -14,7 +15,8 @@ typedef int tS3_effect_tag;
 typedef long tS3_priority;
 typedef long tS3_pitch;
 typedef long tS3_speed;
-typedef char* tS3_outlet_ptr;
+typedef struct tS3_outlet tS3_outlet;
+typedef tS3_outlet* tS3_outlet_ptr;
 
 typedef void tS3_sample_filter(tS3_effect_tag, tS3_sound_tag);
 
@@ -25,14 +27,13 @@ typedef struct tS3_vector3 {
 } tS3_vector3;
 
 int S3Init(char* path, int low_memory_mode);
-void S3Shutdown();
+void S3Shutdown(void);
 
-void S3Disable();
-void S3Enable();
+void S3Disable(void);
+void S3Enable(void);
 
 void S3Set3DSoundEnvironment(float a1, float a2, float a3);
-tS3_sound_source_ptr S3CreateSoundSourceBR(br_vector3* pPosition, br_vector3* pVelocity, tS3_outlet_ptr pBound_outlet);
-int S3BindAmbientSoundToOutlet(tS3_outlet_ptr pOutlet, int pSound, tS3_sound_source_ptr source, float pMax_distance, int pPeriod, int pRepeats, int pVolume, int pPitch, int pSpeed);
+int S3BindAmbientSoundToOutlet(tS3_outlet_ptr pOutlet, int pSound, tS3_sound_source* source, float pMax_distance, int pPeriod, int pRepeats, int pVolume, int pPitch, int pSpeed);
 
 tS3_sound_tag S3StartSound3D(tS3_outlet_ptr pOutlet, tS3_sound_id pSound, tS3_vector3* pInitial_position, tS3_vector3* pInitial_velocity, tS3_repeats pRepeats, tS3_volume pVolume, tS3_pitch pPitch, tS3_speed pSpeed);
 
@@ -48,18 +49,14 @@ void S3Service(int inside_cockpit, int unk1);
 int S3LoadSample(tS3_sound_id id);
 tS3_sound_tag S3StartSound(tS3_outlet_ptr pOutlet, tS3_sound_id pSound);
 tS3_sound_tag S3StartSound2(tS3_outlet_ptr pOutlet, tS3_sound_id pSound, tS3_repeats pRepeats, tS3_volume pLVolume, tS3_volume pRVolume, tS3_pitch pPitch, tS3_speed pSpeed);
-void S3StopAllOutletSounds();
+void S3StopAllOutletSounds(void);
 int S3SoundStillPlaying(tS3_sound_tag pSound);
 int S3StopSound(tS3_sound_tag pSound_tag);
 int S3StopOutletSound(tS3_outlet_ptr pOutlet);
 int S3SetOutletVolume(tS3_outlet_ptr pOutlet, tS3_volume pVolume);
 void S3UpdateSoundSource(tS3_outlet_ptr outlet, tS3_sound_tag tag, tS3_sound_source_ptr src, float pMax_distance_squared, int pPeriod, tS3_repeats pAmbient_repeats, tS3_volume pVolume, int pPitch, tS3_speed pSpeed);
 
-void S3BindListenerPositionBRender(br_vector3* pos);
-void S3BindListenerVelocityBRender(br_vector3* vel);
-void S3BindListenerLeftBRender(br_vector3* left);
-
-int S3IsCDAPlaying2();
+int S3IsCDAPlaying2(void);
 
 int S3SetEffects(tS3_sample_filter* filter1, tS3_sample_filter* filter2);
 
diff --git a/src/S3/include/s3/s3_brender.h b/src/S3/include/s3/s3_brender.h
new file mode 100644
index 00000000..43fa0ba3
--- /dev/null
+++ b/src/S3/include/s3/s3_brender.h
@@ -0,0 +1,14 @@
+#ifndef S3_S3_BRENDER_H
+#define S3_S3_BRENDER_H
+
+#include "s3.h"
+
+#include "brender/brender.h"
+
+tS3_sound_source_ptr S3CreateSoundSourceBR(br_vector3* pPosition, br_vector3* pVelocity, tS3_outlet_ptr pBound_outlet);
+
+void S3BindListenerPositionBRender(br_vector3* pos);
+void S3BindListenerVelocityBRender(br_vector3* vel);
+void S3BindListenerLeftBRender(br_vector3* left);
+
+#endif /* S3_S3_BRENDER_H */
diff --git a/src/S3/s3_defs.h b/src/S3/s3_defs.h
index 1ee06c2b..32d8a4a5 100644
--- a/src/S3/s3_defs.h
+++ b/src/S3/s3_defs.h
@@ -1,6 +1,8 @@
 #ifndef S3_TYPES_H
 #define S3_TYPES_H
 
+#include "s3/s3.h"
+
 #include <stdint.h>
 
 // extern int PDGetTotalTime();
@@ -12,7 +14,7 @@
 // Internal typedefs
 
 typedef float tF32;
-typedef char* tS3_sound_source_ptr;
+typedef tS3_sound_source* tS3_sound_source_ptr;
 typedef int tS3_sound_tag;
 typedef int tS3_sound_id;
 typedef int tS3_type;
@@ -22,11 +24,11 @@ typedef int tS3_effect_tag;
 typedef long tS3_priority;
 typedef long tS3_pitch;
 typedef long tS3_speed;
-typedef char* tS3_outlet_ptr;
 typedef struct tS3_outlet tS3_outlet;
 typedef struct tS3_descriptor tS3_descriptor;
 typedef struct tS3_channel tS3_channel;
 typedef struct tS3_sound_source tS3_sound_source;
+typedef tS3_outlet* tS3_outlet_ptr;
 
 typedef enum tS3_error_codes {
     eS3_error_none = 0,
@@ -72,12 +74,6 @@ typedef enum tS3_sound_type {
 typedef void tS3_outlet_callback(tS3_outlet*, tS3_sound_tag, tS3_termination_reason);
 typedef void tS3_sample_filter(tS3_effect_tag, tS3_sound_tag);
 
-typedef struct tS3_vector3 {
-    tF32 x;
-    tF32 y;
-    tF32 z;
-} tS3_vector3;
-
 typedef struct tS3_channel {
     int active;
     int termination_reason;
diff --git a/src/S3/s3cda.h b/src/S3/s3cda.h
index d88216c8..d780e4fa 100644
--- a/src/S3/s3cda.h
+++ b/src/S3/s3cda.h
@@ -3,13 +3,13 @@
 
 #include "s3_defs.h"
 
-void S3DisableCDA();
-void S3StopCDAOutlets();
+void S3DisableCDA(void);
+void S3StopCDAOutlets(void);
 
 int S3PlayCDA(tS3_channel* chan);
 int S3StopCDA(tS3_channel* chan);
 int S3SetCDAVolume(tS3_channel* chan, int pVolume);
-int S3IsCDAPlaying();
-int S3IsCDAPlaying2();
+int S3IsCDAPlaying(void);
+int S3IsCDAPlaying2(void);
 
 #endif
diff --git a/src/S3/s3music.h b/src/S3/s3music.h
index 22a4ebd6..65e4db6c 100644
--- a/src/S3/s3music.h
+++ b/src/S3/s3music.h
@@ -3,8 +3,8 @@
 
 #include "s3_defs.h"
 
-void S3DisableMIDI();
-void S3StopMIDIOutlets();
+void S3DisableMIDI(void);
+void S3StopMIDIOutlets(void);
 void S3DisposeMIDIChannel(tS3_sound_tag);
 int S3PlayMIDI(tS3_channel* chan);
 int S3MIDILoadSong(tS3_channel* chan);
diff --git a/src/S3/s3sound.c b/src/S3/s3sound.c
index 31e96670..b4ab571f 100644
--- a/src/S3/s3sound.c
+++ b/src/S3/s3sound.c
@@ -342,6 +342,7 @@ int S3SyncSampleRate(tS3_channel* chan) {
     return 1;
 }
 
-void S3SetEffects(tS3_sample_filter* filter1, tS3_sample_filter* filter2) {
+int S3SetEffects(tS3_sample_filter* filter1, tS3_sample_filter* filter2) {
     STUB_ONCE();
+    return 0;
 }
diff --git a/src/harness/CMakeLists.txt b/src/harness/CMakeLists.txt
index 5b9bd93c..9cfb8784 100644
--- a/src/harness/CMakeLists.txt
+++ b/src/harness/CMakeLists.txt
@@ -32,6 +32,9 @@ if(NOT MSVC)
         -Wextra
         -Wno-unused-parameter
     )
+    add_compile_flags_if_supported(harness
+        -Wstrict-prototypes
+    )
 else()
     target_compile_definitions(harness PRIVATE -D_CRT_SECURE_NO_WARNINGS)
 endif()
@@ -60,8 +63,9 @@ target_sources(harness PRIVATE
     sound/sound.c
     sound/sound.h
     win95/polyfill.c
+    platforms/null.c
     platforms/null.h
-    
+
     "${CMAKE_CURRENT_BINARY_DIR}/version.h"
 )
 
diff --git a/src/harness/brender_emu/renderer_impl.h b/src/harness/brender_emu/renderer_impl.h
index d80d794a..a1c13699 100644
--- a/src/harness/brender_emu/renderer_impl.h
+++ b/src/harness/brender_emu/renderer_impl.h
@@ -38,6 +38,6 @@ typedef struct harness_br_renderer {
 
 } harness_br_renderer;
 
-harness_br_renderer* NewHarnessBrRenderer();
+harness_br_renderer* NewHarnessBrRenderer(void);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/harness/harness.c b/src/harness/harness.c
index d88ec26d..b9899921 100644
--- a/src/harness/harness.c
+++ b/src/harness/harness.c
@@ -22,7 +22,7 @@ br_pixelmap* last_src = NULL;
 unsigned int last_frame_time = 0;
 int force_null_platform = 0;
 
-extern unsigned int GetTotalTime();
+extern unsigned int GetTotalTime(void);
 
 extern br_v1db_state v1db;
 extern uint32_t gI_am_cheating;
@@ -80,11 +80,11 @@ static int splatpack_xmasdemo_ascii_shift_table[128] = {
 };
 /* clang-format on */
 
-extern void Harness_Platform_Init();
+extern void Harness_Platform_Init(tHarness_platform* platform);
 
 int Harness_ProcessCommandLine(int* argc, char* argv[]);
 
-void Harness_DetectGameMode() {
+static void Harness_DetectGameMode(void) {
     if (access("DATA/RACES/CASTLE.TXT", F_OK) != -1) {
         // All splatpack edition have the castle track
         if (access("DATA/RACES/CASTLE2.TXT", F_OK) != -1) {
@@ -320,7 +320,7 @@ void Harness_Hook_BrV1dbRendererBegin(br_v1db_state* v1db) {
     v1db->renderer = (br_renderer*)renderer_state;
 }
 
-int Harness_CalculateFrameDelay() {
+static int Harness_CalculateFrameDelay(void) {
     if (harness_game_config.fps == 0) {
         return 0;
     }
@@ -363,7 +363,7 @@ void Harness_Hook_BrPixelmapDoubleBuffer(br_pixelmap* dst, br_pixelmap* src) {
 void Harness_RenderLastScreen() {
     if (last_dst) {
         Harness_RenderScreen(last_dst, last_src);
-        gHarness_platform.SwapWindow(0);
+        gHarness_platform.SwapWindow();
     }
 }
 
diff --git a/src/harness/harness.h b/src/harness/harness.h
index 76c418da..0ea14cb1 100644
--- a/src/harness/harness.h
+++ b/src/harness/harness.h
@@ -4,13 +4,13 @@
 #include "brender/br_types.h"
 #include "harness/trace.h"
 
-void Harness_ForceNullPlatform();
+void Harness_ForceNullPlatform(void);
 
 typedef struct tCamera {
-    void (*update)();
-    float* (*getProjection)();
-    float* (*getView)();
-    void (*setPosition)();
+    void (*update)(void);
+    float* (*getProjection)(void);
+    float* (*getView)(void);
+    void (*setPosition)(void);
 } tCamera;
 
 #endif
diff --git a/src/harness/include/harness/hooks.h b/src/harness/include/harness/hooks.h
index 50a6b407..b5e57743 100644
--- a/src/harness/include/harness/hooks.h
+++ b/src/harness/include/harness/hooks.h
@@ -17,13 +17,13 @@ typedef struct tHarness_platform {
     // Called when beginning a 3D scene
     void (*Renderer_BeginScene)(br_actor* camera, br_pixelmap* colour_buffer, br_pixelmap* depth_buffer);
     // Called at the end of a 3D scene
-    void (*Renderer_EndScene)();
+    void (*Renderer_EndScene)(void);
     // Render a fullscreen quad using the specified pixel data
     void (*Renderer_FullScreenQuad)(uint8_t* src);
     // Render a model
     void (*Renderer_Model)(br_actor* actor, br_model* model, br_material* material, br_token render_type, br_matrix34 model_matrix);
     // Clear frame and depth buffers
-    void (*Renderer_ClearBuffers)();
+    void (*Renderer_ClearBuffers)(void);
     // Load pixelmap into video memory
     void (*Renderer_BufferTexture)(br_pixelmap* pm);
     // Load material
@@ -31,7 +31,7 @@ typedef struct tHarness_platform {
     // Load model into video memory
     void (*Renderer_BufferModel)(br_model* model);
     // Pull contents of frame and depth buffers from video into main memory for software effects
-    void (*Renderer_FlushBuffers)();
+    void (*Renderer_FlushBuffers)(void);
     // Set the 256 color palette to use (BGRA format)
     void (*Renderer_SetPalette)(PALETTEENTRY_* palette);
     // Set the viewport for 3d rendering
@@ -55,9 +55,9 @@ typedef struct tHarness_platform {
     // Sleep
     void (*Sleep)(uint32_t dwMilliseconds);
     // Get ticks
-    uint32_t (*GetTicks)();
+    uint32_t (*GetTicks)(void);
     // Swap window
-    void (*SwapWindow)();
+    void (*SwapWindow)(void);
 
 } tHarness_platform;
 
@@ -74,11 +74,11 @@ void Harness_Hook_renderActor(br_actor* actor, br_model* model, br_material* mat
 
 // Sound hooks
 void Harness_Hook_S3Service(int unk1, int unk2);
-void Harness_Hook_S3StopAllOutletSounds();
+void Harness_Hook_S3StopAllOutletSounds(void);
 
 // Filesystem hooks
 FILE* Harness_Hook_fopen(const char* pathname, const char* mode);
 
-void Harness_RenderLastScreen();
+void Harness_RenderLastScreen(void);
 
 #endif
diff --git a/src/harness/include/harness/win95_polyfill.h b/src/harness/include/harness/win95_polyfill.h
index 1a9bb626..1d08fb34 100644
--- a/src/harness/include/harness/win95_polyfill.h
+++ b/src/harness/include/harness/win95_polyfill.h
@@ -37,7 +37,7 @@ int GetCursorPos_(POINT_* lpPoint);
 
 int ScreenToClient_(void* hWnd, POINT_* lpPoint);
 
-uint32_t timeGetTime_();
+uint32_t timeGetTime_(void);
 
 uint32_t GetCurrentDirectoryA_(uint32_t nBufferLength, char* lpBuffer);
 
@@ -75,7 +75,7 @@ int GetMessageA_(MSG_* lpMsg, void* hWnd, unsigned int wMsgFilterMin, unsigned i
 
 void Sleep_(uint32_t dwMilliseconds);
 
-void DirectDraw_CreateSurface();
+void DirectDraw_CreateSurface(int width, int height);
 
 void DirectDrawDevice_SetPaletteEntries(PALETTEENTRY_* palette, int pFirst_colour, int pCount);
 
diff --git a/src/harness/os/linux.c b/src/harness/os/linux.c
index b02e5e44..42ac59d8 100644
--- a/src/harness/os/linux.c
+++ b/src/harness/os/linux.c
@@ -46,7 +46,7 @@ static int dl_iterate_callback(struct dl_phdr_info* info, size_t size, void* dat
     return 0;
 }
 
-static intptr_t get_dethrace_offset() {
+static intptr_t get_dethrace_offset(void) {
     if (!dethrace_dl_data.initialized) {
         dethrace_dl_data.initialized = 1;
         dl_iterate_phdr(dl_iterate_callback, &dethrace_dl_data);
@@ -65,7 +65,7 @@ int addr2line(char const* const program_name, void const* const addr) {
     return system(addr2line_cmd);
 }
 
-void print_stack_trace() {
+static void print_stack_trace(void) {
     int i, trace_size = 0;
     char** messages = (char**)NULL;
 
diff --git a/src/harness/os/macos.c b/src/harness/os/macos.c
index 04306c6c..dfb4ea4f 100644
--- a/src/harness/os/macos.c
+++ b/src/harness/os/macos.c
@@ -37,7 +37,7 @@ int addr2line(char const* const program_name, void const* const addr) {
     return system(addr2line_cmd);
 }
 
-void print_stack_trace() {
+static void print_stack_trace(void) {
     int i, trace_size = 0;
     char** messages = (char**)NULL;
 
diff --git a/src/harness/platforms/null.c b/src/harness/platforms/null.c
new file mode 100644
index 00000000..935e09ac
--- /dev/null
+++ b/src/harness/platforms/null.c
@@ -0,0 +1,98 @@
+#include "null.h"
+
+// todo: shouldnt depend on sdl...
+#include <SDL.h>
+
+static void* null_create_window_and_renderer(char* title, int x, int y, int width, int height) {
+    return 0;
+}
+
+static int null_set_window_pos(void* hWnd, int x, int y, int nWidth, int nHeight) {
+    return 0;
+}
+
+static void null_destroy_window(void* hWnd) {
+}
+
+static int null_get_and_handle_message(MSG_* msg) {
+    return 0;
+}
+
+static void null_swap_window(void) {
+}
+
+static void null_get_keyboard_state(unsigned int count, uint8_t* buffer) {
+}
+
+static int null_get_mouse_buttons(int* pButton1, int* pButton2) {
+    return 0;
+}
+
+static int null_get_mouse_position(int* pX, int* pY) {
+    return 0;
+}
+
+static int null_show_cursor(int show) {
+    return 0;
+}
+
+static void NullRenderer_BeginScene(br_actor* camera, br_pixelmap* colour_buffer, br_pixelmap* depth_buffer) {
+}
+
+static void NullRenderer_EndScene(void) {
+}
+
+static void NullRenderer_SetPalette(PALETTEENTRY_* palette) {
+}
+
+static void NullRenderer_FullScreenQuad(uint8_t* src) {
+}
+
+static void NullRenderer_Model(br_actor* actor, br_model* model, br_material* material, br_token render_type, br_matrix34 model_matrix) {
+}
+
+static void NullRenderer_ClearBuffers(void) {
+}
+
+static void NullRenderer_BufferTexture(br_pixelmap* pm) {
+}
+
+static void NullRenderer_BufferMaterial(br_material* mat) {
+}
+
+static void NullRenderer_BufferModel(br_model* model) {
+}
+
+static void NullRenderer_FlushBuffers(void) {
+}
+
+static void NullRenderer_SetViewport(int x, int y, int width, int height) {
+}
+
+void Null_Platform_Init(tHarness_platform* platform) {
+    platform->ProcessWindowMessages = null_get_and_handle_message;
+    // todo: shouldnt depend on sdl...
+    platform->Sleep = SDL_Delay;
+    platform->GetTicks = SDL_GetTicks;
+    platform->CreateWindowAndRenderer = null_create_window_and_renderer;
+    platform->ShowCursor = null_show_cursor;
+    platform->SetWindowPos = null_set_window_pos;
+    platform->SwapWindow = null_swap_window;
+    platform->DestroyWindow = null_destroy_window;
+    platform->GetKeyboardState = null_get_keyboard_state;
+    platform->GetMousePosition = null_get_mouse_position;
+    platform->GetMouseButtons = null_get_mouse_buttons;
+    platform->DestroyWindow = null_destroy_window;
+
+    platform->Renderer_BufferModel = NullRenderer_BufferModel;
+    platform->Renderer_BufferMaterial = NullRenderer_BufferMaterial;
+    platform->Renderer_BufferTexture = NullRenderer_BufferTexture;
+    platform->Renderer_SetPalette = NullRenderer_SetPalette;
+    platform->Renderer_FullScreenQuad = NullRenderer_FullScreenQuad;
+    platform->Renderer_Model = NullRenderer_Model;
+    platform->Renderer_ClearBuffers = NullRenderer_ClearBuffers;
+    platform->Renderer_FlushBuffers = NullRenderer_FlushBuffers;
+    platform->Renderer_BeginScene = NullRenderer_BeginScene;
+    platform->Renderer_EndScene = NullRenderer_EndScene;
+    platform->Renderer_SetViewport = NullRenderer_SetViewport;
+}
diff --git a/src/harness/platforms/null.h b/src/harness/platforms/null.h
index c43aa5ac..93a5536a 100644
--- a/src/harness/platforms/null.h
+++ b/src/harness/platforms/null.h
@@ -2,82 +2,7 @@
 #define PLATFORM_NULL
 
 #include "harness/hooks.h"
-// todo: shouldnt depend on sdl...
-#include <SDL.h>
 
-void* null_create_window_and_renderer(char* title, int x, int y, int width, int height) {
-    return 0;
-}
-
-int null_set_window_pos(void* hWnd, int x, int y, int nWidth, int nHeight) {
-    return 0;
-}
-
-void null_destroy_window(void* hWnd) {
-}
-
-int null_get_and_handle_message(MSG_* msg) {
-    return 0;
-}
-
-void null_swap_window() {
-}
-
-void null_get_keyboard_state(unsigned int count, uint8_t* buffer) {
-}
-
-int null_get_mouse_buttons(int* pButton1, int* pButton2) {
-    return 0;
-}
-
-int null_get_mouse_position(int* pX, int* pY) {
-    return 0;
-}
-
-int null_show_cursor(int show) {
-    return 0;
-}
-
-void NullRenderer_Init() {}
-void NullRenderer_BeginScene(br_actor* camera, br_pixelmap* colour_buffer, br_pixelmap* depth_buffer) {}
-void NullRenderer_EndScene() {}
-void NullRenderer_SetPalette(PALETTEENTRY_* palette) {}
-void NullRenderer_FullScreenQuad(uint8_t* src) {}
-void NullRenderer_Model(br_actor* actor, br_model* model, br_material* material, br_token render_type, br_matrix34 model_matrix) {}
-void NullRenderer_RenderFrameBuffer() {}
-void NullRenderer_ClearBuffers() {}
-void NullRenderer_BufferTexture(br_pixelmap* pm) {}
-void NullRenderer_BufferMaterial(br_material* mat) {}
-void NullRenderer_BufferModel(br_model* model) {}
-void NullRenderer_FlushBuffers() {}
-void NullRenderer_SetViewport(int x, int y, int width, int height) {}
-
-void Null_Platform_Init(tHarness_platform* platform) {
-    platform->ProcessWindowMessages = null_get_and_handle_message;
-    // todo: shouldnt depend on sdl...
-    platform->Sleep = SDL_Delay;
-    platform->GetTicks = SDL_GetTicks;
-    platform->CreateWindowAndRenderer = null_create_window_and_renderer;
-    platform->ShowCursor = null_show_cursor;
-    platform->SetWindowPos = null_set_window_pos;
-    platform->SwapWindow = null_swap_window;
-    platform->DestroyWindow = null_destroy_window;
-    platform->GetKeyboardState = null_get_keyboard_state;
-    platform->GetMousePosition = null_get_mouse_position;
-    platform->GetMouseButtons = null_get_mouse_buttons;
-    platform->DestroyWindow = null_destroy_window;
-
-    platform->Renderer_BufferModel = NullRenderer_BufferModel;
-    platform->Renderer_BufferMaterial = NullRenderer_BufferMaterial;
-    platform->Renderer_BufferTexture = NullRenderer_BufferTexture;
-    platform->Renderer_SetPalette = NullRenderer_SetPalette;
-    platform->Renderer_FullScreenQuad = NullRenderer_FullScreenQuad;
-    platform->Renderer_Model = NullRenderer_Model;
-    platform->Renderer_ClearBuffers = NullRenderer_ClearBuffers;
-    platform->Renderer_FlushBuffers = NullRenderer_FlushBuffers;
-    platform->Renderer_BeginScene = NullRenderer_BeginScene;
-    platform->Renderer_EndScene = NullRenderer_EndScene;
-    platform->Renderer_SetViewport = NullRenderer_SetViewport;
-}
+void Null_Platform_Init(tHarness_platform* platform);
 
 #endif
diff --git a/src/harness/platforms/sdl_opengl.c b/src/harness/platforms/sdl_opengl.c
index 5161f5a5..29eb7208 100644
--- a/src/harness/platforms/sdl_opengl.c
+++ b/src/harness/platforms/sdl_opengl.c
@@ -26,7 +26,7 @@ struct {
     float y;
 } sdl_window_scale;
 
-static void update_viewport() {
+static void update_viewport(void) {
     const float target_aspect_ratio = (float)render_width / render_height;
     const float aspect_ratio = (float)window_width / window_height;
 
@@ -44,7 +44,7 @@ static void update_viewport() {
     GLRenderer_SetViewport(vp_x, vp_y, vp_width, vp_height);
 }
 
-void* create_window_and_renderer(char* title, int x, int y, int width, int height) {
+static void* create_window_and_renderer(char* title, int x, int y, int width, int height) {
     window_width = width;
     window_height = height;
     render_width = width;
@@ -96,7 +96,7 @@ void* create_window_and_renderer(char* title, int x, int y, int width, int heigh
     return window;
 }
 
-int set_window_pos(void* hWnd, int x, int y, int nWidth, int nHeight) {
+static int set_window_pos(void* hWnd, int x, int y, int nWidth, int nHeight) {
     // SDL_SetWindowPosition(hWnd, x, y);
     if (nWidth == 320 && nHeight == 200) {
         nWidth = 640;
@@ -106,7 +106,7 @@ int set_window_pos(void* hWnd, int x, int y, int nWidth, int nHeight) {
     return 0;
 }
 
-void destroy_window(void* hWnd) {
+static void destroy_window(void* hWnd) {
     SDL_GL_DeleteContext(context);
     SDL_DestroyWindow(window);
     SDL_Quit();
@@ -119,7 +119,7 @@ static int is_only_key_modifier(int modifier_flags, int flag_check) {
     return (modifier_flags & flag_check) && (modifier_flags & (KMOD_CTRL | KMOD_SHIFT | KMOD_ALT | KMOD_GUI)) == (modifier_flags & flag_check);
 }
 
-int get_and_handle_message(MSG_* msg) {
+static int get_and_handle_message(MSG_* msg) {
     SDL_Event event;
     int dinput_key;
 
@@ -171,22 +171,22 @@ int get_and_handle_message(MSG_* msg) {
     return 0;
 }
 
-void swap_window() {
+static void swap_window(void) {
     SDL_GL_SwapWindow(window);
 }
 
-void get_keyboard_state(unsigned int count, uint8_t* buffer) {
+static void get_keyboard_state(unsigned int count, uint8_t* buffer) {
     memcpy(buffer, directinput_key_state, count);
 }
 
-int get_mouse_buttons(int* pButton1, int* pButton2) {
+static int get_mouse_buttons(int* pButton1, int* pButton2) {
     int state = SDL_GetMouseState(NULL, NULL);
     *pButton1 = state & SDL_BUTTON_LMASK;
     *pButton2 = state & SDL_BUTTON_RMASK;
     return 0;
 }
 
-int get_mouse_position(int* pX, int* pY) {
+static int get_mouse_position(int* pX, int* pY) {
     SDL_GetMouseState(pX, pY);
 
     if (*pX < vp_x) {
@@ -215,7 +215,7 @@ int get_mouse_position(int* pX, int* pY) {
     return 0;
 }
 
-void set_palette(PALETTEENTRY_* pal) {
+static void set_palette(PALETTEENTRY_* pal) {
     GLRenderer_SetPalette((uint8_t*)pal);
 }
 
diff --git a/src/harness/renderers/gl/gl_renderer.c b/src/harness/renderers/gl/gl_renderer.c
index ef0c066e..17877508 100644
--- a/src/harness/renderers/gl/gl_renderer.c
+++ b/src/harness/renderers/gl/gl_renderer.c
@@ -74,7 +74,7 @@ struct {
     GLuint pixels, palette;
 } uniforms_2d;
 
-GLuint CreateShaderProgram(char* name, const char* vertex_shader, const int vertex_shader_len, const char* fragment_shader, const int fragment_shader_len) {
+static GLuint CreateShaderProgram(char* name, const char* vertex_shader, const int vertex_shader_len, const char* fragment_shader, const int fragment_shader_len) {
     int success;
     char log_buffer[1024];
     GLuint program;
@@ -117,7 +117,7 @@ GLuint CreateShaderProgram(char* name, const char* vertex_shader, const int vert
     return program;
 }
 
-GLint GetValidatedUniformLocation(GLuint program, char* uniform_name) {
+static GLint GetValidatedUniformLocation(GLuint program, char* uniform_name) {
     GLint location;
     location = glGetUniformLocation(program, uniform_name);
     if (location == -1) {
@@ -126,7 +126,7 @@ GLint GetValidatedUniformLocation(GLuint program, char* uniform_name) {
     return location;
 }
 
-void LoadShaders() {
+static void LoadShaders(void) {
     shader_program_2d = CreateShaderProgram("framebuffer", RESOURCES_FRAMEBUFFER_VERT_GLSL, sizeof(RESOURCES_FRAMEBUFFER_VERT_GLSL), RESOURCES_FRAMEBUFFER_FRAG_GLSL, sizeof(RESOURCES_FRAMEBUFFER_FRAG_GLSL));
     glUseProgram(shader_program_2d);
     uniforms_2d.pixels = GetValidatedUniformLocation(shader_program_2d, "u_pixels");
@@ -172,7 +172,7 @@ void LoadShaders() {
     glUniform1i(uniforms_3d.colour_buffer_texture, 4);
 }
 
-void SetupFullScreenRectGeometry() {
+static void SetupFullScreenRectGeometry(void) {
     float vertices[] = {
         // positions          // colors           // texture coords
         1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top right
diff --git a/src/harness/renderers/gl/gl_renderer.h b/src/harness/renderers/gl/gl_renderer.h
index aa0c06c6..fd59e530 100644
--- a/src/harness/renderers/gl/gl_renderer.h
+++ b/src/harness/renderers/gl/gl_renderer.h
@@ -45,15 +45,15 @@
 void GLRenderer_Init(int render_width, int render_height);
 void GLRenderer_SetPalette(uint8_t* rgba_colors);
 void GLRenderer_BeginScene(br_actor* camera, br_pixelmap* colour_buffer, br_pixelmap* depth_buffer);
-void GLRenderer_EndScene();
+void GLRenderer_EndScene(void);
 void GLRenderer_FullScreenQuad(uint8_t* screen_buffer);
 void GLRenderer_Model(br_actor* actor, br_model* model, br_material* material, br_token render_type, br_matrix34 model_matrix);
 void GLRenderer_BufferTexture(br_pixelmap* pm);
 void GLRenderer_BufferMaterial(br_material* mat);
 void GLRenderer_BufferModel(br_model* model);
-void GLRenderer_ClearBuffers();
+void GLRenderer_ClearBuffers(void);
 void GLRenderer_FlushBuffer(tRenderer_flush_type flush_type);
-void GLRenderer_FlushBuffers();
+void GLRenderer_FlushBuffers(void);
 void GLRenderer_SetViewport(int x, int y, int width, int height);
 
 #endif
diff --git a/src/harness/renderers/gl/stored_context.h b/src/harness/renderers/gl/stored_context.h
index 5b7d7ba6..a4220111 100644
--- a/src/harness/renderers/gl/stored_context.h
+++ b/src/harness/renderers/gl/stored_context.h
@@ -24,10 +24,10 @@ typedef struct tStored_material {
     char identifier[200];
 } tStored_material;
 
-tStored_model_context* NewStoredModelContext();
+tStored_model_context* NewStoredModelContext(void);
 
-tStored_material* NewStoredMaterial();
+tStored_material* NewStoredMaterial(void);
 
-tStored_pixelmap* NewStoredPixelmap();
+tStored_pixelmap* NewStoredPixelmap(void);
 
 #endif
diff --git a/src/harness/sound/sound.h b/src/harness/sound/sound.h
index 1ab49c22..19919060 100644
--- a/src/harness/sound/sound.h
+++ b/src/harness/sound/sound.h
@@ -2,7 +2,7 @@
 #ifndef HARNESS_SOUND_H
 #define HARNESS_SOUND_H
 
-void Sound_Init();
-void Sound_Service();
+void Sound_Init(void);
+void Sound_Service(void);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/smackw32/CMakeLists.txt b/src/smackw32/CMakeLists.txt
index 9fc34969..2c31c02e 100644
--- a/src/smackw32/CMakeLists.txt
+++ b/src/smackw32/CMakeLists.txt
@@ -10,7 +10,9 @@ target_include_directories(smackw32
 target_link_libraries(smackw32 PRIVATE harness brender libsmacker compile_with_werror)
 
 if(NOT MSVC)
-    
+    add_compile_flags_if_supported(smackw32
+        -Wstrict-prototypes
+    )
 else()
     target_compile_definitions(smackw32 PRIVATE -D_CRT_SECURE_NO_WARNINGS)
     target_compile_options(smackw32 PRIVATE