diff --git a/include/haproxy/h2.h b/include/haproxy/h2.h
index aa0edec93..e4eaccafe 100644
--- a/include/haproxy/h2.h
+++ b/include/haproxy/h2.h
@@ -212,6 +212,8 @@ int h2_make_htx_trailers(struct http_hdr *list, struct htx *htx);
 /* returns a bit corresponding to the frame type */
 static inline unsigned int h2_ft_bit(enum h2_ft ft)
 {
+	if (ft >= H2_FT_ENTRIES)
+		return 0;
 	return 1U << ft;
 }