diff --git a/src/audio.h b/src/audio.h
index da02da84ac..ff72448b79 100644
--- a/src/audio.h
+++ b/src/audio.h
@@ -437,11 +437,6 @@ typedef union SeqArgs {
     } UnkCmdFF;
 } SeqArgs;
 
-typedef union VolumeField {
-    u16 u16;
-    s32 s32;
-} VolumeField;
-
 /// Structure for volume fading for SFX and BGM. Has independent controls for base and envelope volumes.
 typedef struct Fade {
     /* 0x0 */ s16_16 baseVolume;
@@ -452,7 +447,7 @@ typedef struct Fade {
     /* 0xC */ AuCallback onCompleteCallback;
     /* 0xC */ s32 variation;
               };
-    /* 0x10 */ VolumeField envelopeVolume;
+    /* 0x10 */ s16_16 envelopeVolume;
     /* 0x14 */ s32 envelopeStep;
     /* 0x18 */ s16 envelopeTarget;
     /* 0x1A */ s16 envelopeTicks;
diff --git a/src/audio/bgm_player.c b/src/audio/bgm_player.c
index 93765b1053..50a220c526 100644
--- a/src/audio/bgm_player.c
+++ b/src/audio/bgm_player.c
@@ -637,7 +637,10 @@ void au_bgm_update_fade(BGMPlayer* player) {
 }
 
 void au_bgm_update_bus_volumes(BGMPlayer* player) {
-    u16 volume = (((u32)player->fadeInfo.baseVolume >> 16) * player->fadeInfo.envelopeVolume.u16) >> 15;
+    u16 volume = (
+            ((u32)player->fadeInfo.baseVolume >> 16) *
+            ((u32)player->fadeInfo.envelopeVolume >> 16)
+        ) >> 15;
     s32 i;
 
     for (i = 0; i < ARRAY_COUNT(player->effectIndices); i++) {
@@ -1837,7 +1840,10 @@ void au_BGMCmd_FF(BGMPlayer* player, BGMPlayerTrack* track) {
                     if ((player->soundManager->bgmSounds[i].index) == 0) {
                         player->soundManager->bgmSounds[i].index = arg1;
                         player->soundManager->bgmSounds[i].volume =
-                            ((s32)(((u32)player->fadeInfo.baseVolume >> 16) * player->fadeInfo.envelopeVolume.u16) + AU_MAX_VOLUME_16) >> 0x17;
+                            ((s32)(
+                                ((u32)player->fadeInfo.baseVolume >> 16) *
+                                ((u32)player->fadeInfo.envelopeVolume >> 16)
+                            ) + AU_MAX_VOLUME_16) >> 0x17;
                         break;
                     }
                 }
diff --git a/src/audio/core/engine.c b/src/audio/core/engine.c
index 458ef1992c..44854bcfbb 100644
--- a/src/audio/core/engine.c
+++ b/src/audio/core/engine.c
@@ -461,7 +461,7 @@ void au_fade_flush(Fade* fade) {
 }
 
 void au_fade_set_vol_scale(Fade* fade, s16 value) {
-    fade->envelopeVolume.s32 = value << 16;
+    fade->envelopeVolume = value << 16;
     fade->envelopeTarget = value;
     fade->envelopeTicks = 0;
     fade->envelopeStep = 0;
@@ -473,7 +473,7 @@ void au_unk_80053B04(Fade* fade, u32 duration, s32 target) {
 
     if (duration >= 250 && duration <= 100000) {
         ticks = (s32)(duration * 1000) / AU_FRAME_USEC;
-        delta = (target << 16) - fade->envelopeVolume.s32;
+        delta = (target << 16) - fade->envelopeVolume;
 
         fade->envelopeTarget = target;
         fade->envelopeTicks = ticks;
@@ -488,10 +488,10 @@ void au_fade_update_envelope(Fade* fade) {
     fade->envelopeTicks--;
 
     if (fade->envelopeTicks != 0) {
-        fade->envelopeVolume.s32 += fade->envelopeStep;
+        fade->envelopeVolume += fade->envelopeStep;
     } else {
         fade->envelopeStep = 0;
-        fade->envelopeVolume.s32 = fade->envelopeTarget << 16;
+        fade->envelopeVolume = fade->envelopeTarget << 16;
     }
 }