diff --git a/src/mux_h2.c b/src/mux_h2.c
index 8a54e3a0c..7546e04a6 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -6236,6 +6236,13 @@ next_frame:
 
 	/* Skip StreamDep and weight for now (we don't support PRIORITY) */
 	if (h2c->dff & H2_F_HEADERS_PRIORITY) {
+		if (flen < 5) {
+			h2c_report_glitch(h2c, 1, "too short PRIORITY frame");
+			TRACE_STATE("too short PRIORITY frame", H2_EV_RX_FRAME|H2_EV_RX_HDR|H2_EV_H2C_ERR|H2_EV_PROTO_ERR, h2c->conn);
+			h2c_error(h2c, H2_ERR_FRAME_SIZE_ERROR);
+			goto fail;
+		}
+
 		if (read_n32(hdrs) == h2c->dsi) {
 			/* RFC7540#5.3.1 : stream dep may not depend on itself */
 			h2c_report_glitch(h2c, 1, "PRIORITY frame referencing itself");
@@ -6245,13 +6252,6 @@ next_frame:
 			goto fail;
 		}
 
-		if (flen < 5) {
-			h2c_report_glitch(h2c, 1, "too short PRIORITY frame");
-			TRACE_STATE("too short PRIORITY frame", H2_EV_RX_FRAME|H2_EV_RX_HDR|H2_EV_H2C_ERR|H2_EV_PROTO_ERR, h2c->conn);
-			h2c_error(h2c, H2_ERR_FRAME_SIZE_ERROR);
-			goto fail;
-		}
-
 		hdrs += 5; // stream dep = 4, weight = 1
 		flen -= 5;
 	}