diff --git a/bsp/k210/Kconfig b/bsp/k210/Kconfig
index ccb4adf6dc78f9d5cda2a2d36e06794f5a845b88..3d1f1315f5285605cc965f2f760ba3e1c2f4fd97 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