diff --git a/mercurial/mpatch.c b/mercurial/mpatch.c
--- a/mercurial/mpatch.c
+++ b/mercurial/mpatch.c
@@ -23,8 +23,21 @@
 #include <Python.h>
 #include <stdlib.h>
 #include <string.h>
-#include <netinet/in.h>
-#include <sys/types.h>
+#ifdef _WIN32
+
+typedef unsigned long uint32_t;
+
+uint32_t ntohl(uint32_t x) {
+  return ((x & 0x000000ffUL) << 24) |
+         ((x & 0x0000ff00UL) <<  8) |
+         ((x & 0x00ff0000UL) >>  8) |
+         ((x & 0xff000000UL) >> 24);
+}
+
+#else
+  #include <netinet/in.h>
+  #include <sys/types.h>
+#endif
 
 static char mpatch_doc[] = "Efficient binary patching.";