diff --git a/headers/modsecurity/collection/collection.h b/headers/modsecurity/collection/collection.h
index 25d86b9a67..352dfb7702 100644
--- a/headers/modsecurity/collection/collection.h
+++ b/headers/modsecurity/collection/collection.h
@@ -21,6 +21,7 @@
 #include <vector>
 #include <algorithm>
 #include <memory>
+#include <cstdint>
 #endif