1 files changed, 4 insertions, 3 deletions
diff --git a/packages/core/src/tools/modifiable-tool.ts b/packages/core/src/tools/modifiable-tool.ts
index e935a704..419aafeb 100644
--- a/packages/core/src/tools/modifiable-tool.ts
+++ b/packages/core/src/tools/modifiable-tool.ts
@@ -58,15 +58,16 @@ function createTempFilesForModify(
     fs.mkdirSync(diffDir, { recursive: true });
   }
 
-  const fileName = path.basename(file_path);
+  const ext = path.extname(file_path);
+  const fileName = path.basename(file_path, ext);
   const timestamp = Date.now();
   const tempOldPath = path.join(
     diffDir,
-    `gemini-cli-modify-${fileName}-old-${timestamp}`,
+    `gemini-cli-modify-${fileName}-old-${timestamp}${ext}`,
   );
   const tempNewPath = path.join(
     diffDir,
-    `gemini-cli-modify-${fileName}-new-${timestamp}`,
+    `gemini-cli-modify-${fileName}-new-${timestamp}${ext}`,
   );
 
   fs.writeFileSync(tempOldPath, currentContent, 'utf8');