diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index d77790fe02..d54f1454b1 100644
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -197,6 +197,9 @@ proc parseUntil*(s: string, token: var string, until: string,
   ## parses a token and stores it in ``token``. Returns
   ## the number of the parsed characters or 0 in case of an error. A token
   ## consists of any character that comes before the `until`  token.
+  if until.len == 0:
+    token.setLen(0)
+    return 0
   var i = start
   while i < s.len:
     if s[i] == until[0]: