diff --git a/src/modules/simulator/simulator_params.c b/src/modules/simulator/simulator_params.c
index 23ee0280e6..7a39320d2c 100644
--- a/src/modules/simulator/simulator_params.c
+++ b/src/modules/simulator/simulator_params.c
@@ -53,6 +53,7 @@ PARAM_DEFINE_INT32(SITL_UDP_PRT, 14560);
  * @min 1
  * @max 86400
  * @increment 1
+ * @unit s
  *
  * @group SITL
  */