diff --git a/layer2/CifFile.h b/layer2/CifFile.h
index c6414acd8..c4f1664e6 100644
--- a/layer2/CifFile.h
+++ b/layer2/CifFile.h
@@ -8,6 +8,7 @@
 #define _H_CIFFILE
 
 #include <cstddef>
+#include <cstdint>
 #include <cstring>
 #include <map>
 #include <memory>