diff --git a/src/w_wad.c b/src/w_wad.c
index b94e39c7e..13d1ae785 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -891,7 +891,7 @@ UINT16 W_InitFile(const char *filename, boolean mainfile, boolean startup, wadco
 		wadfile->compatmode = CheckCompatZip(numwadfiles - 1);
 		break;
 	default:
-		wadfile->compatmode = false;
+		wadfile->compatmode = CheckCompatFilename(filename);
 		break;
 	}