diff --git a/pjmedia/src/pjmedia/null_port.c b/pjmedia/src/pjmedia/null_port.c
index 97b8a8b..ca50c53 100644
--- a/pjmedia/src/pjmedia/null_port.c
+++ b/pjmedia/src/pjmedia/null_port.c
@@ -46,7 +46,7 @@
     PJ_ASSERT_RETURN(pool && p_port, PJ_EINVAL);
 
     port = PJ_POOL_ZALLOC_T(pool, pjmedia_port);
-    PJ_ASSERT_RETURN(pool != NULL, PJ_ENOMEM);
+    PJ_ASSERT_RETURN(port != NULL, PJ_ENOMEM);
 
     pjmedia_port_info_init(&port->info, &name, SIGNATURE, sampling_rate,
 			   channel_count, bits_per_sample, samples_per_frame);