diff --git a/lib/libtags/tags.c b/lib/libtags/tags.c
index 750d9077..b1d6ac33 100644
--- a/lib/libtags/tags.c
+++ b/lib/libtags/tags.c
@@ -71,7 +71,9 @@ tagsget(Tagctx *ctx)
 	for(i = 0; i < nelem(g); i++){
 		ctx->num = 0;
 		if(g[i].f(ctx) == 0){
-			ctx->format = g[i].format;
+			if(ctx->format == Funknown){
+				ctx->format = g[i].format;
+			}
 			res = 0;
 		}
 		ctx->seek(ctx, ctx->restart, 0);