diff --git a/src/index.ts b/src/index.ts
index aec2646..8d9e112 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -84,7 +84,7 @@ export async function createIntegrityMetadata(
   if (!supportedHashAlgorithm.includes(alg)) return "";
 
   const arrayBuffer = await crypto.subtle.digest(
-    supportedHashAlgorithmName[alg.toLowerCase()],
+    supportedHashAlgorithmName[alg],
     data,
   );