diff --git a/src/contrib/average.h b/src/contrib/average.h
index 857215efb..e6b8d4fc6 100644
--- a/src/contrib/average.h
+++ b/src/contrib/average.h
@@ -24,6 +24,7 @@
 #include <cmath>
 #include <ostream>
 #include <limits>
+#include <stdint.h>
 
 namespace ns3 {