diff --git a/.gitignore b/.gitignore
index 6a51c542f8c..95be12e84a4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ docs/doxygen/
 
 # IDE
 .vscode/
+.idea/
 
 # Python
 __pycache__/
diff --git a/tools/extract_game_assets.py b/tools/extract_game_assets.py
index 1cfdf6ee30a..9ae1777c959 100644
--- a/tools/extract_game_assets.py
+++ b/tools/extract_game_assets.py
@@ -9,6 +9,7 @@ Extracts the game assets and stores them in the game folder
 Usage: `python tools/extract_game_assets.py`
 """
 
+fileMagicNumber = b"GZ2E01"
 fstInfoPosition = 0x424
 bootPosition = 0x0
 bootSize = 0x440
@@ -243,6 +244,13 @@ def extract(isoPath: Path, gamePath: Path, yaz0Encoder):
     cwd = os.getcwd()
     os.chdir(gamePath)
     with open(isoPath, "rb") as f:
+        magic = f.read(len(fileMagicNumber))
+        if magic != fileMagicNumber:
+            if magic.startswith(b"CISO"):
+                raise RuntimeError("Compressed ISO files are not supported.")
+            else:
+                raise RuntimeError(f"Invalid ISO magic number: expected {fileMagicNumber}, got {magic}")
+
         # Seek to fst offset information and retrieve it
         f.seek(fstInfoPosition)
         fstOffset, fstSize = getFstInfo(f, fstInfoPosition)
diff --git a/tools/requirements.txt b/tools/requirements.txt
index d2717753943..fc6011a52a4 100644
--- a/tools/requirements.txt
+++ b/tools/requirements.txt
@@ -10,4 +10,5 @@ cxxfilt
 pyelftools
 requests
 GitPython
-clang
\ No newline at end of file
+clang
+pyyaml