diff --git a/src/mongo/util/ctype.h b/src/mongo/util/ctype.h
index a3880e2..78ee57e 100644
--- a/src/mongo/util/ctype.h
+++ b/src/mongo/util/ctype.h
@@ -67,6 +67,7 @@
 #pragma once

 #include <array>
+#include <cstdint>

 namespace mongo::ctype {
 namespace detail {