diff --git a/src/extension.ts b/src/extension.ts
index bd04cd9..8709706 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -12,7 +12,7 @@ function format(document: TextDocument): Promise<TextEdit[]> {
   return new Promise((resolve, reject) => {
     // Create mix command
     const mixFormatArgs: string = workspace.getConfiguration("elixir.formatter").get("mixFormatArgs") || "";
-    const cmd = `mix format ${mixFormatArgs} ${document.fileName}`;
+    const cmd = `mix format ${mixFormatArgs} "${document.fileName}"`;
 
     // Figure out the working directory to run mix format in
     const workspaceRootPath = workspace.rootPath ? workspace.rootPath : "";
@@ -46,4 +46,4 @@ export function activate(context: ExtensionContext) {
       });
     }
   });
-}
\ No newline at end of file
+}