diff --git a/lib/rewriter.js b/lib/rewriter.js
index 86cecec1..ee9e3042 100644
--- a/lib/rewriter.js
+++ b/lib/rewriter.js
@@ -138,7 +138,7 @@
     });
   };
   exports.Rewriter.prototype.addImplicitBraces = function() {
-    var action, condition, stack;
+    var action, condition, stack, start;
     stack = [];
     condition = function(token, i) {
       var _ref, _ref2, one, tag, three, two;
@@ -147,26 +147,27 @@
       }
       _ref = this.tokens.slice(i + 1, i + 4), one = _ref[0], two = _ref[1], three = _ref[2];
       tag = token[0];
-      return (tag === 'TERMINATOR' || tag === 'OUTDENT') && !((two != null ? two[0] : undefined) === ':' || (one != null ? one[0] : undefined) === '@' && (three != null ? three[0] : undefined) === ':') || tag === ',' && ((_ref2 = one != null ? one[0] : undefined) !== 'IDENTIFIER' && _ref2 !== 'NUMBER' && _ref2 !== 'STRING' && _ref2 !== '@' && _ref2 !== 'TERMINATOR' && _ref2 !== 'OUTDENT');
+      return (tag === 'TERMINATOR' || tag === 'OUTDENT') && !((two != null ? two[0] : undefined) === ':' || (one != null ? one[0] : undefined) === '@' && (three != null ? three[0] : undefined) === ':' || (one != null ? one[0] : undefined) === '(') || tag === ',' && one && ((_ref2 = one[0]) !== 'IDENTIFIER' && _ref2 !== 'NUMBER' && _ref2 !== 'STRING' && _ref2 !== '@' && _ref2 !== 'TERMINATOR' && _ref2 !== 'OUTDENT' && _ref2 !== '(');
     };
     action = function(token, i) {
       return this.tokens.splice(i, 0, ['}', '}', token[2]]);
     };
+    start = null;
     return this.scanTokens(function(token, i, tokens) {
-      var _ref, idx, tag, tok;
+      var _ref, _ref2, idx, tag, tok;
       if (_ref = (tag = token[0]), __indexOf.call(EXPRESSION_START, _ref) >= 0) {
-        stack.push(tag === 'INDENT' && this.tag(i - 1) === '{' ? '{' : tag);
+        stack.push([(tag === 'INDENT' && this.tag(i - 1) === '{' ? '{' : tag), i]);
         return 1;
       }
       if (__indexOf.call(EXPRESSION_END, tag) >= 0) {
-        stack.pop();
+        start = stack.pop();
         return 1;
       }
-      if (!(tag === ':' && stack[stack.length - 1] !== '{')) {
+      if (!(tag === ':' && ((_ref2 = stack[stack.length - 1]) != null ? _ref2[0] : undefined) !== '{')) {
         return 1;
       }
-      stack.push('{');
-      idx = this.tag(i - 2) === '@' ? i - 2 : i - 1;
+      stack.push(['{']);
+      idx = this.tag(i - 1) === ')' ? start[1] : this.tag(i - 2) === '@' ? i - 2 : i - 1;
       if (this.tag(idx - 2) === 'HERECOMMENT') {
         idx -= 2;
       }
diff --git a/src/rewriter.coffee b/src/rewriter.coffee
index 501653cf..dbe6bb8e 100644
--- a/src/rewriter.coffee
+++ b/src/rewriter.coffee
@@ -124,19 +124,27 @@ class exports.Rewriter
       return false if 'HERECOMMENT' in [@tag(i + 1), @tag(i - 1)]
       [one, two, three] = @tokens.slice i + 1, i + 4
       [tag] = token
-      tag in ['TERMINATOR', 'OUTDENT'] and not (two?[0] is ':' or one?[0] is '@' and three?[0] is ':') or
-      tag is ',' and one?[0] not in ['IDENTIFIER', 'NUMBER', 'STRING', '@', 'TERMINATOR', 'OUTDENT']
+      tag in ['TERMINATOR', 'OUTDENT'] and
+        not (two?[0] is ':' or one?[0] is '@' and three?[0] is ':' or one?[0] is '(') or
+      tag is ',' and one and
+        one[0] not in ['IDENTIFIER', 'NUMBER', 'STRING', '@', 'TERMINATOR', 'OUTDENT', '(']
     action = (token, i) -> @tokens.splice i, 0, ['}', '}', token[2]]
+    start = null
     @scanTokens (token, i, tokens) ->
       if (tag = token[0]) in EXPRESSION_START
-        stack.push if tag is 'INDENT' and @tag(i - 1) is '{' then '{' else tag
+        stack.push [(if tag is 'INDENT' and @tag(i - 1) is '{' then '{' else tag), i]
         return 1
       if tag in EXPRESSION_END
-        stack.pop()
+        start = stack.pop()
         return 1
-      return 1 unless tag is ':' and stack[stack.length - 1] isnt '{'
-      stack.push '{'
-      idx = if @tag(i - 2) is '@' then i - 2 else i - 1
+      return 1 unless tag is ':' and stack[stack.length - 1]?[0] isnt '{'
+      stack.push ['{']
+      idx = if @tag(i - 1) is ')'
+        start[1]
+      else  if @tag(i - 2) is '@'
+        i - 2
+      else
+        i - 1
       idx -= 2 if @tag(idx - 2) is 'HERECOMMENT'
       tok = ['{', '{', token[2]]
       tok.generated = yes
diff --git a/test/test_literals.coffee b/test/test_literals.coffee
index c7010caf..5658a4b2 100644
--- a/test/test_literals.coffee
+++ b/test/test_literals.coffee
@@ -245,6 +245,9 @@ eq obj.interpolatedkey, 123
 eq obj[8], 8
 eq obj[1], 1
 
+eq 'braceless dynamic key',
+  (key for key of """braceless #{ 0 of ((0):(0)) and 'dynamic' } key""": 0)[0]
+
 
 #542: Objects leading expression statement should be parenthesized.
 {f: -> ok yes }.f() + 1