diff --git a/index.ts b/index.ts
index 3e022ab..97a4b2c 100644
--- a/index.ts
+++ b/index.ts
@@ -401,7 +401,9 @@ async function createOrUpdateFile(
   content: string,
   commitMessage: string,
   branch: string,
-  previousPath?: string
+  previousPath?: string,
+  last_commit_id?: string,
+  commit_id?: string
 ): Promise<GitLabCreateUpdateFileResponse> {
   const encodedPath = encodeURIComponent(filePath);
   const url = new URL(
@@ -410,7 +412,7 @@ async function createOrUpdateFile(
     )}/repository/files/${encodedPath}`
   );
 
-  const body = {
+  const body: Record<string, any> = {
     branch,
     content,
     commit_message: commitMessage,
@@ -421,13 +423,37 @@ async function createOrUpdateFile(
   // Check if file exists
   let method = "POST";
   try {
-    await getFileContents(projectId, filePath, branch);
+    // Get file contents to check existence and retrieve commit IDs
+    const fileData = await getFileContents(projectId, filePath, branch);
     method = "PUT";
+
+    // If fileData is not an array, it's a file content object with commit IDs
+    if (!Array.isArray(fileData)) {
+      // Use commit IDs from the file data if not provided in parameters
+      if (!commit_id && fileData.commit_id) {
+        body.commit_id = fileData.commit_id;
+      } else if (commit_id) {
+        body.commit_id = commit_id;
+      }
+
+      if (!last_commit_id && fileData.last_commit_id) {
+        body.last_commit_id = fileData.last_commit_id;
+      } else if (last_commit_id) {
+        body.last_commit_id = last_commit_id;
+      }
+    }
   } catch (error) {
     if (!(error instanceof Error && error.message.includes("File not found"))) {
       throw error;
     }
-    // File doesn't exist, use POST
+    // File doesn't exist, use POST - no need for commit IDs for new files
+    // But still use any provided as parameters if they exist
+    if (commit_id) {
+      body.commit_id = commit_id;
+    }
+    if (last_commit_id) {
+      body.last_commit_id = last_commit_id;
+    }
   }
 
   const response = await fetch(url.toString(), {
@@ -934,7 +960,9 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
           args.content,
           args.commit_message,
           args.branch,
-          args.previous_path
+          args.previous_path,
+          args.last_commit_id,
+          args.commit_id
         );
         return {
           content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
diff --git a/schemas.ts b/schemas.ts
index fa1ae3b..f8bc29b 100644
--- a/schemas.ts
+++ b/schemas.ts
@@ -43,7 +43,9 @@ export const GitLabFileContentSchema = z.object({
   content_sha256: z.string(), // Changed from sha to match GitLab API
   ref: z.string(), // Added as GitLab requires branch reference
   blob_id: z.string(), // Added to match GitLab API
+  commit_id: z.string(), // ID of the current file version
   last_commit_id: z.string(), // Added to match GitLab API
+  execute_filemode: z.boolean().optional(), // Added to match GitLab API
 });
 
 export const GitLabDirectoryContentSchema = z.object({
@@ -138,7 +140,7 @@ export const CreateBranchOptionsSchema = z.object({
 export const GitLabCreateUpdateFileResponseSchema = z.object({
   file_path: z.string(),
   branch: z.string(),
-  commit_id: z.string(), // Changed from sha to match GitLab API
+  commit_id: z.string().optional(), // Optional since it's not always returned by the API
   content: GitLabFileContentSchema.optional(),
 });
 
@@ -263,6 +265,14 @@ export const CreateOrUpdateFileSchema = ProjectParamsSchema.extend({
     .string()
     .optional()
     .describe("Path of the file to move/rename"),
+  last_commit_id: z
+    .string()
+    .optional()
+    .describe("Last known file commit ID"),
+  commit_id: z
+    .string()
+    .optional()
+    .describe("Current file commit ID (for update operations)"),
 });
 
 export const SearchRepositoriesSchema = z.object({