diff --git a/openbsc/tests/gbproxy/gbproxy_test.c b/openbsc/tests/gbproxy/gbproxy_test.c
index 10f3a26..a3768ae 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.c
+++ b/openbsc/tests/gbproxy/gbproxy_test.c
@@ -346,7 +346,7 @@
 {
 	/* GPRS Network Service, PDU type: NS_UNITDATA, BVCI 0
 	 * BSSGP RESET */
-	unsigned char msg[22] = {
+	unsigned char msg[18] = {
 		0x22, 0x04, 0x82, 0x4a,
 		0x2e, 0x07, 0x81, 0x08, 0x08, 0x88, 0x11, 0x22,
 		0x33, 0x40, 0x50, 0x60, 0x10, 0x00