diff --git a/src/hnbgw_hnbap.c b/src/hnbgw_hnbap.c
index 65e5cc9..cdd4895 100644
--- a/src/hnbgw_hnbap.c
+++ b/src/hnbgw_hnbap.c
@@ -16,6 +16,9 @@
 
 static int hnbgw_hnbap_tx(struct hnb_context *ctx, struct msgb *msg)
 {
+	if (!msg)
+		return -EINVAL;
+
 	msgb_ppid(msg) = IUH_PPI_HNBAP;
 	return osmo_wqueue_enqueue(&ctx->wqueue, msg);
 }