diff --git a/source/ps/GameSetup/GameSetup.cpp b/source/ps/GameSetup/GameSetup.cpp
index 327a9e933d..f239d054f1 100644
--- a/source/ps/GameSetup/GameSetup.cpp
+++ b/source/ps/GameSetup/GameSetup.cpp
@@ -408,7 +408,7 @@ ErrorReactionInternal psDisplayError(const wchar_t* UNUSED(text), size_t UNUSED(
 	return ERI_NOT_IMPLEMENTED;
 }
 
-std::vector<CStr>& GetMods(const CmdLineArgs& args, int flags)
+const std::vector<CStr>& GetMods(const CmdLineArgs& args, int flags)
 {
 	const bool init_mods = (flags & INIT_MODS) == INIT_MODS;
 	const bool add_user = !InDevelopmentCopy() && !args.Has("noUserMod");
diff --git a/source/ps/GameSetup/GameSetup.h b/source/ps/GameSetup/GameSetup.h
index 3a02fa23d8..12f22e6626 100644
--- a/source/ps/GameSetup/GameSetup.h
+++ b/source/ps/GameSetup/GameSetup.h
@@ -78,7 +78,7 @@ extern void RenderCursor(bool RenderingState);
 
 class CmdLineArgs;
 class Paths;
-extern std::vector<CStr>& GetMods(const CmdLineArgs& args, int flags);
+extern const std::vector<CStr>& GetMods(const CmdLineArgs& args, int flags);
 extern void MountMods(const Paths& paths, const std::vector<CStr>& mods);
 /**
  * Returns true if successful, false if mods changed and restart_engine was called.