diff --git a/lib/expression/node/ArrayNode.js b/lib/expression/node/ArrayNode.js
index 4d9d05c82..caf7a6078 100644
--- a/lib/expression/node/ArrayNode.js
+++ b/lib/expression/node/ArrayNode.js
@@ -99,7 +99,7 @@ ArrayNode.prototype.toString = function() {
  * @param {String} type
  * @return {String} str
  */
-ArrayNode.prototype.toTex = function(customFunctions, type) {
+ArrayNode.prototype._toTex = function(customFunctions, type) {
   type = type || 'bmatrix';
   var s = '\\begin{' + type + '}';
 
diff --git a/lib/expression/node/AssignmentNode.js b/lib/expression/node/AssignmentNode.js
index 1223166da..ce9da5cfc 100644
--- a/lib/expression/node/AssignmentNode.js
+++ b/lib/expression/node/AssignmentNode.js
@@ -92,7 +92,7 @@ AssignmentNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String}
  */
-AssignmentNode.prototype.toTex = function(customFunctions) {
+AssignmentNode.prototype._toTex = function(customFunctions) {
   var precedence = operators.getPrecedence(this);
   var exprPrecedence = operators.getPrecedence(this.expr);
 
diff --git a/lib/expression/node/BlockNode.js b/lib/expression/node/BlockNode.js
index 9f674ba50..90b2d1a14 100644
--- a/lib/expression/node/BlockNode.js
+++ b/lib/expression/node/BlockNode.js
@@ -125,7 +125,7 @@ BlockNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-BlockNode.prototype.toTex = function(customFunctions) {
+BlockNode.prototype._toTex = function(customFunctions) {
   return this.blocks.map(function (param) {
     return param.node.toTex(customFunctions) + (param.visible ? '' : ';');
   }).join('\n');
diff --git a/lib/expression/node/ConditionalNode.js b/lib/expression/node/ConditionalNode.js
index 1ab699f12..29f4c9ff3 100644
--- a/lib/expression/node/ConditionalNode.js
+++ b/lib/expression/node/ConditionalNode.js
@@ -154,7 +154,7 @@ ConditionalNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-ConditionalNode.prototype.toTex = function(customFunctions) {
+ConditionalNode.prototype._toTex = function(customFunctions) {
   var s = (
       latex.addBraces(this.trueExpr.toTex(customFunctions)) +
       ', &\\quad' +
diff --git a/lib/expression/node/ConstantNode.js b/lib/expression/node/ConstantNode.js
index f50071886..dd001315e 100644
--- a/lib/expression/node/ConstantNode.js
+++ b/lib/expression/node/ConstantNode.js
@@ -159,7 +159,7 @@ ConstantNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-ConstantNode.prototype.toTex = function(customFunctions) {
+ConstantNode.prototype._toTex = function(customFunctions) {
   var value = this.value,
       index;
   switch (this.valueType) {
diff --git a/lib/expression/node/FunctionAssignmentNode.js b/lib/expression/node/FunctionAssignmentNode.js
index 97138fca0..5718c0908 100644
--- a/lib/expression/node/FunctionAssignmentNode.js
+++ b/lib/expression/node/FunctionAssignmentNode.js
@@ -113,7 +113,7 @@ FunctionAssignmentNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-FunctionAssignmentNode.prototype.toTex = function(customFunctions) {
+FunctionAssignmentNode.prototype._toTex = function(customFunctions) {
   var precedence = operators.getPrecedence(this);
   var exprPrecedence = operators.getPrecedence(this.expr);
 
diff --git a/lib/expression/node/FunctionNode.js b/lib/expression/node/FunctionNode.js
index 1f613855c..eaeee60d2 100644
--- a/lib/expression/node/FunctionNode.js
+++ b/lib/expression/node/FunctionNode.js
@@ -116,7 +116,7 @@ FunctionNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-FunctionNode.prototype.toTex = function(customFunctions) {
+FunctionNode.prototype._toTex = function(customFunctions) {
   return latex.toArgs(this, customFunctions);
 };
 
diff --git a/lib/expression/node/IndexNode.js b/lib/expression/node/IndexNode.js
index d6bd5b995..175826630 100644
--- a/lib/expression/node/IndexNode.js
+++ b/lib/expression/node/IndexNode.js
@@ -212,7 +212,7 @@ IndexNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-IndexNode.prototype.toTex = function(customFunctions) {
+IndexNode.prototype._toTex = function(customFunctions) {
   return this.object.toTex(customFunctions) + '[' + this.ranges.join(', ') + ']';
 };
 
diff --git a/lib/expression/node/Node.js b/lib/expression/node/Node.js
index 5b97d5693..fcd8d5cc3 100644
--- a/lib/expression/node/Node.js
+++ b/lib/expression/node/Node.js
@@ -222,10 +222,23 @@ Node.prototype.toString = function() {
 
 /**
  * Get LaTeX representation
+ * @param {Object|function} callback(s)
  * @return {String}
  */
-Node.prototype.toTex = function() {
-  return '';
+Node.prototype.toTex = function(customFunctions) {
+  return this._toTex(customFunctions);
+};
+
+/**
+ * Internal function to generate the LaTeX output.
+ * This has to be implemented by every Node
+ *
+ * @param {Object}|function}
+ * @throws {Error}
+ */
+Node.prototype._toTex = function () {
+  //must be implemented by each of the Node implementations
+  throw new Error('_toTex not implemented for this Node');
 };
 
 /**
diff --git a/lib/expression/node/OperatorNode.js b/lib/expression/node/OperatorNode.js
index 9a02e79e6..986fed1af 100644
--- a/lib/expression/node/OperatorNode.js
+++ b/lib/expression/node/OperatorNode.js
@@ -239,7 +239,7 @@ OperatorNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String} str
  */
-OperatorNode.prototype.toTex = function(customFunctions) {
+OperatorNode.prototype._toTex = function(customFunctions) {
  var args = this.args; 
  var parens = calculateNecessaryParentheses(this, args);
  var op = latex.toOperator(this.op); //operator
diff --git a/lib/expression/node/RangeNode.js b/lib/expression/node/RangeNode.js
index 7702c6f6c..f28cfc156 100644
--- a/lib/expression/node/RangeNode.js
+++ b/lib/expression/node/RangeNode.js
@@ -124,7 +124,7 @@ RangeNode.prototype.toString = function() {
  * @params {Object|function} callback(s)
  * @return {String} str
  */
-RangeNode.prototype.toTex = function(customFunctions) {
+RangeNode.prototype._toTex = function(customFunctions) {
   var str = this.start.toTex(customFunctions);
   if (this.step) {
     str += ':' + this.step.toTex(customFunctions);
diff --git a/lib/expression/node/SymbolNode.js b/lib/expression/node/SymbolNode.js
index cb3ff1ad8..34409fe80 100644
--- a/lib/expression/node/SymbolNode.js
+++ b/lib/expression/node/SymbolNode.js
@@ -103,7 +103,7 @@ SymbolNode.prototype.toString = function() {
  * @return {String} str
  * @override
  */
-SymbolNode.prototype.toTex = function(customFunctions) {
+SymbolNode.prototype._toTex = function(customFunctions) {
   return latex.toSymbol(this.name, customFunctions);
 };
 
diff --git a/lib/expression/node/UpdateNode.js b/lib/expression/node/UpdateNode.js
index f48c8cb46..346504ff6 100644
--- a/lib/expression/node/UpdateNode.js
+++ b/lib/expression/node/UpdateNode.js
@@ -87,7 +87,7 @@ UpdateNode.prototype.toString = function() {
  * @param {Object|function} callback(s)
  * @return {String}
  */
-UpdateNode.prototype.toTex = function(customFunctions) {
+UpdateNode.prototype._toTex = function(customFunctions) {
   return this.index.toTex(customFunctions) + ' = ' + this.expr.toTex(customFunctions);
 };
 
diff --git a/test/expression/node/Node.test.js b/test/expression/node/Node.test.js
index 355856d16..02589a4e7 100644
--- a/test/expression/node/Node.test.js
+++ b/test/expression/node/Node.test.js
@@ -74,9 +74,11 @@ describe('Node', function() {
     assert.equal(node.toString(), '');
   });
 
-  it ('should LaTeX a Node', function () {
-    var node = new Node();
-    assert.equal(node.toTex(), '');
+  it ('should throw an error when calling toTex', function () {
+    assert.throws(function () {
+      var node = new Node();
+      node.toTex();
+    }, /_toTex not implemented for this Node/);
   });
 
   it ('should throw an error in case of wrong arguments for compile', function () {