diff --git a/stepmania/src/ActorUtil.cpp b/stepmania/src/ActorUtil.cpp
index 7eef6ba278..43106175a1 100644
--- a/stepmania/src/ActorUtil.cpp
+++ b/stepmania/src/ActorUtil.cpp
@@ -86,7 +86,7 @@ Actor* MakeActor( CString sPath )
 		return pModel;
 	}
 
-	ASSERT(0);
-	return NULL;
+	RageException::Throw("File \"%s\" has unknown type, \"%s\"",
+		sPath.c_str(), sExt.c_str() );
 }