diff --git a/src/apps/mqtt/mqtt.c b/src/apps/mqtt/mqtt.c
index 08134116..b3c29467 100644
--- a/src/apps/mqtt/mqtt.c
+++ b/src/apps/mqtt/mqtt.c
@@ -2,7 +2,7 @@
  * @file
  * MQTT client
  *
- * @defgroup mqtt MQTT Client
+ * @defgroup mqtt MQTT client
  * @ingroup apps
  */