diff --git a/.github/workflows/zephyr.yml b/.github/workflows/zephyr.yml
index eb81835c0..7225c6ffa 100644
--- a/.github/workflows/zephyr.yml
+++ b/.github/workflows/zephyr.yml
@@ -87,6 +87,8 @@ jobs:
           mosquitto -c scripts/broker_test/mosquitto.conf &> broker.log &
           sleep 1 # let the broker set everything up
           mosquitto_sub -t sensors &> sub.log &
+        env:
+          WOLFMQTT_NO_EXTERNAL_BROKER_TESTS: 1
 
       # This is some debug info useful if something goes wrong
       - name: Show network status
diff --git a/zephyr/samples/client.c b/zephyr/samples/client.c
index c85f1fde3..2225f66c7 100644
--- a/zephyr/samples/client.c
+++ b/zephyr/samples/client.c
@@ -31,7 +31,14 @@ int main(void)
     mqtt_init_ctx(&mqttCtx);
 
     mqttCtx.test_mode = 1;
-
+#ifdef WOLFMQTT_NO_EXTERNAL_BROKER_TESTS
+    /* Set port as configured in scripts/broker_test/mosquitto.conf */
+#if WOLFMQTT_DEFAULT_TLS
+    mqttCtx.port = 18883;
+#else
+    mqttCtx.port = 11883;
+#endif
+#endif
     rc = mqttclient_test(&mqttCtx);
 
     mqtt_free_ctx(&mqttCtx);