diff --git a/src/w_wad.c b/src/w_wad.c
index b599c271d..68d5a464d 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -382,11 +382,7 @@ static inline boolean CheckCompatFilename(const char *filename)
 static inline boolean CheckCompatExtension(const char *filename)
 {
 	char *basename = strrchr(filename, '.');
-
-	if (!stricmp(basename+1, "KART"))
-		return true;
-
-	return false;
+	return basename && !stricmp(basename+1, "KART");
 }
 
 static inline boolean CheckCompatSkins(UINT16 wadnum)
diff --git a/src/w_wad.h b/src/w_wad.h
index 32436ba2f..e69c09bc3 100644
--- a/src/w_wad.h
+++ b/src/w_wad.h
@@ -68,7 +68,7 @@ struct wadfile_t
 {
 	char *filename;
 	restype_t type;
-	UINT32 *lumphashes; // hashes for every lump's fullname in ALL CAPS
+	UINT32 *lumphashes; // hashes for every lump's longname in ALL CAPS
 	lumpinfo_t *lumpinfo;
 	lumpcache_t *lumpcache;
 	lumpcache_t *patchcache;