diff --git a/src/util/StringView.hxx b/src/util/StringView.hxx
index 4d384d4ed..5db6a0802 100644
--- a/src/util/StringView.hxx
+++ b/src/util/StringView.hxx
@@ -60,7 +60,7 @@ struct StringView : ConstBuffer<char> {
 	}
 
 	gcc_pure
-	pointer_type Find(char ch) const noexcept {
+	pointer_type Find(value_type ch) const noexcept {
 		return (pointer_type)memchr(data, ch, size);
 	}