diff --git a/src/Microsoft.AspNetCore.Identity/UpperInvariantLookupNormalizer.cs b/src/Microsoft.AspNetCore.Identity/UpperInvariantLookupNormalizer.cs
index 2bfa958651..3ab3f9f647 100644
--- a/src/Microsoft.AspNetCore.Identity/UpperInvariantLookupNormalizer.cs
+++ b/src/Microsoft.AspNetCore.Identity/UpperInvariantLookupNormalizer.cs
@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Identity
             {
                 return null;
             }
-            return key.ToUpperInvariant();
+            return key.Normalize().ToUpperInvariant();
         }
     }
 }