--- a/mercurial/mpatch.c
+++ b/mercurial/mpatch.c
@@ -27,11 +27,12 @@
 
 typedef unsigned long uint32_t;
 
-uint32_t ntohl(uint32_t x) {
-  return ((x & 0x000000ffUL) << 24) |
-         ((x & 0x0000ff00UL) <<  8) |
-         ((x & 0x00ff0000UL) >>  8) |
-         ((x & 0xff000000UL) >> 24);
+static uint32_t ntohl(uint32_t x)
+{
+	return ((x & 0x000000ffUL) << 24) |
+		((x & 0x0000ff00UL) <<  8) |
+		((x & 0x00ff0000UL) >>  8) |
+		((x & 0xff000000UL) >> 24);
 }
 
 #else