diff --git a/simgear/package/untar.cxx b/simgear/package/untar.cxx
index 715d2243..9eb0901c 100644
--- a/simgear/package/untar.cxx
+++ b/simgear/package/untar.cxx
@@ -19,6 +19,7 @@
 
 #include <cstdlib>
 #include <cassert>
+#include <cstdint>
 
 #include <zlib.h>