diff --git a/mercurial/bdiff.c b/mercurial/bdiff.c
--- a/mercurial/bdiff.c
+++ b/mercurial/bdiff.c
@@ -10,6 +10,7 @@
 */
 
 #include <Python.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>