diff --git a/patch.py b/patch.py
index 972d4f9..d80d595 100644
--- a/patch.py
+++ b/patch.py
@@ -1,13 +1,49 @@
 import sys
 import getpass
 import os
+import re
 import tempfile
+from pathlib import Path
+
+GAME_RELATIVE = Path('steamapps/common/Trials Rising/datapack/trialsrising.exe')
+
+
+def steam_library_candidates(user):
+    """Yield candidate paths to trialsrising.exe across every Steam library.
+
+    Rather than guessing at device names or mount points (for example, assuming the microSD card
+    is always at /run/media/mmcblk0p1), read Steam's own libraryfolders.vdf, which lists every
+    installed library no matter where it lives (internal drive, SD card, external drive, ...).
+    """
+    home = Path('/home') / user
+    steam_roots = [
+        home / '.local/share/Steam',                                    # standard Linux / SteamOS
+        home / '.steam/steam',                                          # older / symlinked installs
+        home / '.var/app/com.valvesoftware.Steam/.local/share/Steam',   # Flatpak Steam
+        home / 'snap/steam/common/.local/share/Steam',                  # Snap Steam
+    ]
+    for root in steam_roots:
+        # The library that lives directly under the Steam root (usually the default one).
+        yield root / GAME_RELATIVE
+        try:
+            text = (root / 'steamapps' / 'libraryfolders.vdf').read_text(encoding='utf-8', errors='replace')
+        except OSError:
+            continue
+        # Each library root is stored as:  "path"  "/run/media/mmcblk0p1"
+        for library in re.findall(r'"path"\s+"([^"]+)"', text):
+            yield Path(library) / GAME_RELATIVE
+
 
 # Check if user specified a path
 if len(sys.argv) > 1:
     path = sys.argv[1]
 else:
-    path = '/home/' + getpass.getuser() + '/.local/share/Steam/steamapps/common/Trials Rising/datapack/trialsrising.exe'
+    user = getpass.getuser()
+    path = next(
+        (str(candidate) for candidate in steam_library_candidates(user) if candidate.is_file()),
+        # Last-resort default, so the "file not found" hint still names a real location.
+        '/home/' + user + '/.local/share/Steam/' + str(GAME_RELATIVE),
+    )
 
 # Some explanation: these bytes first serve as hex representations of the program instructions we want to change
 # But if that was all they needed to be, they could each be 3 hex characters long: