diff --git a/dir.c b/dir.c
index 7426fde330..4f5a2241e6 100644
--- a/dir.c
+++ b/dir.c
@@ -353,6 +353,9 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, co
 			     !strcmp(de->d_name + 1, "git")))
 				continue;
 			len = strlen(de->d_name);
+			/* Ignore overly long pathnames! */
+			if (len + baselen + 8 > sizeof(fullname))
+				continue;
 			memcpy(fullname + baselen, de->d_name, len+1);
 			if (simplify_away(fullname, baselen + len, simplify))
 				continue;