diff --git a/frontend/.gitignore b/frontend/.gitignore
index b1d1588..c466d90 100644
--- a/frontend/.gitignore
+++ b/frontend/.gitignore
@@ -8,6 +8,9 @@ dist
 dist-ssr
 *.local
 
+# Vite cache
+.vite
+
 # Logs
 logs
 *.log
diff --git a/frontend/src/components/ui/FileDropzone.tsx b/frontend/src/components/ui/FileDropzone.tsx
index 285fd0a..26fee91 100644
--- a/frontend/src/components/ui/FileDropzone.tsx
+++ b/frontend/src/components/ui/FileDropzone.tsx
@@ -122,7 +122,7 @@ export function FileDropzone({
           >
             <input
               type="file"
-              accept=".xlsx,.xls"
+              accept=".xlsx,.xlsm,.xltx,.xltm"
               onChange={handleFileInput}
               disabled={disabled}
               className="sr-only"
@@ -142,7 +142,7 @@ export function FileDropzone({
             <p className="dropzone-text">
               {isDragging ? 'Drop your file here' : 'Drag and drop your Excel file'}
             </p>
-            <p className="dropzone-subtext">or click to browse • XLSX, XLS supported</p>
+            <p className="dropzone-subtext">or click to browse • XLSX supported</p>
 
             {isDragging && (
               <motion.div
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 62618e9..f55d4b3 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -25,5 +25,5 @@ export interface FileInfo {
   file: File;
   name: string;
   size: string;
-  type: 'xlsx' | 'xls';
+  type: 'xlsx' | 'xlsm' | 'xltx' | 'xltm';
 }
diff --git a/pyproject.toml b/pyproject.toml
index bc2a031..75511e9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -63,7 +63,16 @@ packages = ["src/rosetta"]
 exclude = ["src/rosetta/api", "src/rosetta/api/*"]
 
 [tool.hatch.build.targets.sdist]
-exclude = ["src/rosetta/api", "src/rosetta/api/*"]
+exclude = [
+    "src/rosetta/api",
+    "src/rosetta/api/*",
+    "frontend",
+    "frontend/**",
+    "tests",
+    "tests/**",
+    ".github",
+    ".github/**",
+]
 
 [tool.black]
 line-length = 100
diff --git a/src/rosetta/api/app.py b/src/rosetta/api/app.py
index 5a334cb..595b34c 100644
--- a/src/rosetta/api/app.py
+++ b/src/rosetta/api/app.py
@@ -15,7 +15,8 @@
 load_dotenv()
 
 # Limits
-MAX_FILE_SIZE = 10 * 1024 * 1024  # 10MB
+# Keep in sync with frontend validation/copy (50MB).
+MAX_FILE_SIZE = 50 * 1024 * 1024  # 50MB
 MAX_CELLS = 5000
 
 app = FastAPI(
diff --git a/tests/test_api.py b/tests/test_api.py
index ddb2926..dc21023 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -211,9 +211,9 @@ class TestFileSizeLimits:
     """Tests for file size validation."""
 
     def test_large_file_returns_400(self, client):
-        """Files over 10MB should be rejected."""
-        # Create a file larger than 10MB
-        large_content = b"x" * (11 * 1024 * 1024)
+        """Files over 50MB should be rejected."""
+        # Create a file larger than 50MB
+        large_content = b"x" * (51 * 1024 * 1024)
 
         response = client.post(
             "/translate",