diff --git a/lib/expression/node/ParenthesisNode.js b/lib/expression/node/ParenthesisNode.js
index 88c8edb0c..9891b5fbe 100644
--- a/lib/expression/node/ParenthesisNode.js
+++ b/lib/expression/node/ParenthesisNode.js
@@ -83,7 +83,10 @@ function factory (type, config, load, typed) {
    * @override
    */
   ParenthesisNode.prototype._toString = function() {
-    return '(' + this.content._toString() + ')';
+    if (config.parenthesis === 'keep') {
+      return '(' + this.content.toString() + ')';
+    }
+    return this.content._toString();
   };
 
   /**
@@ -93,7 +96,10 @@ function factory (type, config, load, typed) {
    * @override
    */
   ParenthesisNode.prototype._toTex = function(callbacks) {
-    return '\\left(' + this.content.toTex(callbacks) + '\\right)';
+    if (config.parenthesis === 'keep') {
+      return '\\left(' + this.content.toTex(callbacks) + '\\right)';
+    }
+    return this.content.toTex(callbacks);
   };
 
   return ParenthesisNode;
diff --git a/test/expression/node/ParenthesisNode.test.js b/test/expression/node/ParenthesisNode.test.js
index 4c6acaaf8..3f886a731 100644
--- a/test/expression/node/ParenthesisNode.test.js
+++ b/test/expression/node/ParenthesisNode.test.js
@@ -131,10 +131,38 @@ describe('ParenthesisNode', function() {
     assert.equal(n.toString(), '(1)');
   });
 
+  it ('should stringify a ParenthesisNode when not in keep mode', function () {
+    var allMath = math.create({parenthesis: 'all'});
+    var autoMath = math.create({parenthesis: 'auto'});
+
+    var allC = new allMath.expression.node.ConstantNode(1);
+    var autoC = new autoMath.expression.node.ConstantNode(1);
+
+    var allP = new allMath.expression.node.ParenthesisNode(allC);
+    var autoP = new autoMath.expression.node.ParenthesisNode(autoC);
+
+    assert.equal(allP.toString(), '1');
+    assert.equal(autoP.toString(), '1');
+  });
+
   it ('should LaTeX a ParenthesisNode', function () {
     var a = new ConstantNode(1);
     var n = new ParenthesisNode(a);
 
     assert.equal(n.toTex(), '\\left(1\\right)');
   });
+
+  it ('should LaTeX a ParenthesisNode when not in keep mode', function () {
+    var allMath = math.create({parenthesis: 'all'});
+    var autoMath = math.create({parenthesis: 'auto'});
+
+    var allC = new allMath.expression.node.ConstantNode(1);
+    var autoC = new autoMath.expression.node.ConstantNode(1);
+
+    var allP = new allMath.expression.node.ParenthesisNode(allC);
+    var autoP = new autoMath.expression.node.ParenthesisNode(autoC);
+
+    assert.equal(allP.toTex(), '1');
+    assert.equal(autoP.toTex(), '1');
+  });
 });