diff --git a/bsp/k210/Kconfig b/bsp/k210/Kconfig
index ccb4adf6dc..3d1f1315f5 100644
--- a/bsp/k210/Kconfig
+++ b/bsp/k210/Kconfig
@@ -8,7 +8,7 @@ config $BSP_DIR
 config $RTT_DIR
     string
     option env="RTT_ROOT"
-    default: "../.."
+    default "../.."
 
 config $PKGS_DIR
     string