diff --git a/lib/pure/asynchttpserver.nim b/lib/pure/asynchttpserver.nim
index 720455791f..a86d8755c5 100644
--- a/lib/pure/asynchttpserver.nim
+++ b/lib/pure/asynchttpserver.nim
@@ -149,7 +149,7 @@ proc parseProtocol(protocol: string): tuple[orig: string, major, minor: int] =
         protocol)
   result.orig = protocol
   i.inc protocol.parseSaturatedNatural(result.major, i)
-  i.inc # Skip .
+  if i < protocol.len: inc i # Skip .
   i.inc protocol.parseSaturatedNatural(result.minor, i)
 
 proc sendStatus(client: AsyncSocket, status: string): Future[void] =