diff --git a/git-compat-util.h b/git-compat-util.h
index f649e81f11..348b9dcc1c 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -744,6 +744,9 @@ static inline size_t xsize_t(off_t len)
 	return (size_t)len;
 }
 
+__attribute__((format (printf, 3, 4)))
+extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
+
 /* in ctype.c, for kwset users */
 extern const unsigned char tolower_trans_tbl[256];
 
diff --git a/wrapper.c b/wrapper.c
index 0e22d43814..6fcaa4dc62 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -621,6 +621,22 @@ char *xgetcwd(void)
 	return strbuf_detach(&sb, NULL);
 }
 
+int xsnprintf(char *dst, size_t max, const char *fmt, ...)
+{
+	va_list ap;
+	int len;
+
+	va_start(ap, fmt);
+	len = vsnprintf(dst, max, fmt, ap);
+	va_end(ap);
+
+	if (len < 0)
+		die("BUG: your snprintf is broken");
+	if (len >= max)
+		die("BUG: attempt to snprintf into too-small buffer");
+	return len;
+}
+
 static int write_file_v(const char *path, int fatal,
 			const char *fmt, va_list params)
 {