diff --git a/native/jni/src/proximity_info.cpp b/native/jni/src/proximity_info.cpp
index e681f6f..765632e 100644
--- a/native/jni/src/proximity_info.cpp
+++ b/native/jni/src/proximity_info.cpp
@@ -302,6 +302,6 @@
     if (keyId0 >= 0 && keyId1 >= 0) {
         return mKeyKeyDistancesG[keyId0][keyId1];
     }
-    return 0;
+    return MAX_POINT_TO_KEY_LENGTH;
 }
 } // namespace latinime