diff --git a/lib/std/core/string.c3 b/lib/std/core/string.c3
index f5eeecf34..099a82fa5 100644
--- a/lib/std/core/string.c3
+++ b/lib/std/core/string.c3
@@ -540,7 +540,7 @@ fn String String.new_ascii_to_lower(s, Allocator allocator = allocator::heap())
 	return copy;
 }
 
-fn String String.temp_ascii_to_lower(s, Allocator allocator = allocator::heap())
+fn String String.temp_ascii_to_lower(s)
 {
 	return s.new_ascii_to_lower(allocator::temp());
 }