diff --git a/lib/irb/ruby-lex.rb b/lib/irb/ruby-lex.rb
index 879c45c565..ca01662eee 100644
--- a/lib/irb/ruby-lex.rb
+++ b/lib/irb/ruby-lex.rb
@@ -792,7 +792,7 @@ class RubyLex
           token_c = TkSymbol2Token[trans[1]]
           @lex_state = trans[0]
         else
-          if @lex_state != EXPR_FNAME
+          if @lex_state != EXPR_FNAME and peek(0) != ':'
             if ENINDENT_CLAUSE.include?(token)
               # check for ``class = val'' etc.
               valid = true