diff --git a/mozilla/config/nsinstall.c b/mozilla/config/nsinstall.c
index de9efdb2c0e..b46aeaa1a04 100644
--- a/mozilla/config/nsinstall.c
+++ b/mozilla/config/nsinstall.c
@@ -111,8 +111,7 @@ mkdirs(char *path, mode_t mode)
 
     while (*path == '/' && path[1] == '/')
 	path++;
-    while ((cp = strrchr(path, '/')) && cp[1] == '\0')
-	*cp = '\0';
+    for (cp = strrchr(path, '/'); cp && cp != path && *(cp - 1) == '/'; cp--);
     if (cp && cp != path) {
 	*cp = '\0';
 	if ((lstat(path, &sb) < 0 || !S_ISDIR(sb.st_mode)) &&