diff --git a/problems/0093.复原IP地址.md b/problems/0093.复原IP地址.md
index 7910fc50..6401824b 100644
--- a/problems/0093.复原IP地址.md
+++ b/problems/0093.复原IP地址.md
@@ -227,7 +227,7 @@ private:
 public:
     vector<string> restoreIpAddresses(string s) {
         result.clear();
-        if (s.size() > 12) return result; // 算是剪枝了
+        if (s.size() < 4 || s.size() > 12) return result; // 算是剪枝了
         backtracking(s, 0, 0);
         return result;
     }