diff --git a/libbb/concat_path_file.c b/libbb/concat_path_file.c
index d53dc0e..ce92310 100644
--- a/libbb/concat_path_file.c
+++ b/libbb/concat_path_file.c
@@ -15,9 +15,11 @@
 	int  flg_slash = 1;
 
 	l = strlen(path);
-	if(l>0 && path[l-1] == '/')
+	if (l>0 && path[l-1] == '/')
 		flg_slash--;
 	l += strlen(filename);
+	if (l>0 && filename[0] == '/')
+		flg_slash--;
 	outbuf = xmalloc(l+1+flg_slash);
 	sprintf(outbuf, (flg_slash ? "%s/%s" : "%s%s"), path, filename);
 	return outbuf;