diff --git a/lib/irc/msg.ml b/lib/irc/msg.ml
index aacb233..c3fa3ef 100644
--- a/lib/irc/msg.ml
+++ b/lib/irc/msg.ml
@@ -58,9 +58,9 @@ exception Incomplete
 
 let crlf = function '\r' | '\n' | '\x00' -> true | _ -> false
 let cl = function ':' -> true | _ -> false
-let sp = function ' ' -> true | _ -> false
-let nocrlf = function '\r' | '\n' | '\x00' -> false | _ -> true
-let nospcrlf = function ' ' | '\r' | '\n' | '\x00' -> false | _ -> true
+let sp = function ' ' | '\t' -> true | _ -> false
+let nocrlf c = not (crlf c)
+let nospcrlf c = not (sp c || crlf c)
 
 let startswith str f i =
   if i >= String.length str then