diff --git a/git-compat-util.h b/git-compat-util.h
index 8d244d0d9..bf3ceb802 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -46,6 +46,7 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <pwd.h>
+#include <stdint.h>
 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 #include <grp.h>
 #define _ALL_SOURCE 1
diff --git a/pack.h b/pack.h
index 790ff4a39..821706fbc 100644
--- a/pack.h
+++ b/pack.h
@@ -10,9 +10,9 @@
 #define PACK_VERSION 2
 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
 struct pack_header {
-	unsigned int hdr_signature;
-	unsigned int hdr_version;
-	unsigned int hdr_entries;
+	uint32_t hdr_signature;
+	uint32_t hdr_version;
+	uint32_t hdr_entries;
 };
 
 /*