diff --git a/lib/lexer.js b/lib/lexer.js
index 396d2704..958f4043 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -607,7 +607,7 @@
   STRING_NEWLINES = /\n[ \t]*/g;
   NO_NEWLINE = /^([+\*&|\/\-%=<>:!.\\][<>=&|]*|and|or|is|isnt|not|delete|typeof|instanceof)$/;
   HEREDOC_INDENT = /(\n+([ \t]*)|^([ \t]+))/g;
-  ASSIGNED = /^([a-zA-Z\$_]\w*[ \t]*?[:=])/;
+  ASSIGNED = /^([a-zA-Z\$_]\w*[ \t]*?[:=][^=])/;
   NEXT_CHARACTER = /^\s*(\S)/;
   NOT_REGEX = ['NUMBER', 'REGEX', '++', '--', 'FALSE', 'NULL', 'TRUE', ']'];
   CALLABLE = ['IDENTIFIER', 'SUPER', ')', ']', '}', 'STRING', '@', 'THIS', '?', '::'];
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 3cca3924..2244b762 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -530,7 +530,7 @@ MULTILINER      : /\n/g
 STRING_NEWLINES : /\n[ \t]*/g
 NO_NEWLINE      : /^([+\*&|\/\-%=<>:!.\\][<>=&|]*|and|or|is|isnt|not|delete|typeof|instanceof)$/
 HEREDOC_INDENT  : /(\n+([ \t]*)|^([ \t]+))/g
-ASSIGNED        : /^([a-zA-Z\$_]\w*[ \t]*?[:=])/
+ASSIGNED        : /^([a-zA-Z\$_]\w*[ \t]*?[:=][^=])/
 NEXT_CHARACTER  : /^\s*(\S)/
 
 # Tokens which a regular expression will never immediately follow, but which
diff --git a/test/test_literals.coffee b/test/test_literals.coffee
index a062f32e..13e629e3 100644
--- a/test/test_literals.coffee
+++ b/test/test_literals.coffee
@@ -114,3 +114,10 @@ obj: {class: 'höt'}
 obj.function: 'dog'
 
 ok obj.class + obj.function is 'hötdog'
+
+
+# But keyword assignment should be smart enough not to stringify variables.
+func: ->
+  this == 'this'
+
+ok func() is false