diff --git a/src/pages/api/submissions/index.ts b/src/pages/api/submissions/index.ts
index 31d63a8..9af456f 100644
--- a/src/pages/api/submissions/index.ts
+++ b/src/pages/api/submissions/index.ts
@@ -48,6 +48,9 @@ export const POST: APIRoute = async ({ request }) => {
       if (language !== 'python') {
         code = code.replace(/\s+/g, ' ');
       }
+    // Normalize case so "Int", "String", "Char", "Printf" etc.
+    // are treated the same as "int", "string", "char", "printf"
+    code = code.toLowerCase();
       return code;
     };
     const normalizedSubmitted = normalizeCode(submittedCode, challenge.language);