diff --git a/generators/dart/procedures.js b/generators/dart/procedures.js
index dacacdad5..123685fb7 100644
--- a/generators/dart/procedures.js
+++ b/generators/dart/procedures.js
@@ -48,8 +48,9 @@ Blockly.Dart['procedures_defreturn'] = function(block) {
   }
   var returnType = returnValue ? 'dynamic' : 'void';
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
-    args[i] = Blockly.Dart.variableDB_.getName(block.arguments_[i],
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
+    args[i] = Blockly.Dart.variableDB_.getName(variables[i],
         Blockly.VARIABLE_CATEGORY_NAME);
   }
   var code = returnType + ' ' + funcName + '(' + args.join(', ') + ') {\n' +
@@ -69,7 +70,8 @@ Blockly.Dart['procedures_callreturn'] = function(block) {
   var funcName = Blockly.Dart.variableDB_.getName(block.getFieldValue('NAME'),
       Blockly.PROCEDURE_CATEGORY_NAME);
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
     args[i] = Blockly.Dart.valueToCode(block, 'ARG' + i,
         Blockly.Dart.ORDER_NONE) || 'null';
   }
diff --git a/generators/javascript/procedures.js b/generators/javascript/procedures.js
index a987bca02..90fb57d04 100644
--- a/generators/javascript/procedures.js
+++ b/generators/javascript/procedures.js
@@ -49,8 +49,9 @@ Blockly.JavaScript['procedures_defreturn'] = function(block) {
     returnValue = Blockly.JavaScript.INDENT + 'return ' + returnValue + ';\n';
   }
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
-    args[i] = Blockly.JavaScript.variableDB_.getName(block.arguments_[i],
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
+    args[i] = Blockly.JavaScript.variableDB_.getName(variables[i],
         Blockly.VARIABLE_CATEGORY_NAME);
   }
   var code = 'function ' + funcName + '(' + args.join(', ') + ') {\n' +
@@ -71,7 +72,8 @@ Blockly.JavaScript['procedures_callreturn'] = function(block) {
   var funcName = Blockly.JavaScript.variableDB_.getName(
       block.getFieldValue('NAME'), Blockly.PROCEDURE_CATEGORY_NAME);
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
     args[i] = Blockly.JavaScript.valueToCode(block, 'ARG' + i,
         Blockly.JavaScript.ORDER_COMMA) || 'null';
   }
diff --git a/generators/lua/procedures.js b/generators/lua/procedures.js
index f0354c29a..156c3c7d9 100644
--- a/generators/lua/procedures.js
+++ b/generators/lua/procedures.js
@@ -49,8 +49,9 @@ Blockly.Lua['procedures_defreturn'] = function(block) {
     branch = '';
   }
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
-    args[i] = Blockly.Lua.variableDB_.getName(block.arguments_[i],
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
+    args[i] = Blockly.Lua.variableDB_.getName(variables[i],
         Blockly.VARIABLE_CATEGORY_NAME);
   }
   var code = 'function ' + funcName + '(' + args.join(', ') + ')\n' +
@@ -71,7 +72,8 @@ Blockly.Lua['procedures_callreturn'] = function(block) {
   var funcName = Blockly.Lua.variableDB_.getName(
       block.getFieldValue('NAME'), Blockly.PROCEDURE_CATEGORY_NAME);
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
     args[i] = Blockly.Lua.valueToCode(block, 'ARG' + i,
         Blockly.Lua.ORDER_NONE) || 'nil';
   }
diff --git a/generators/php/procedures.js b/generators/php/procedures.js
index e4fe80879..d3b39e477 100644
--- a/generators/php/procedures.js
+++ b/generators/php/procedures.js
@@ -24,7 +24,7 @@ Blockly.PHP['procedures_defreturn'] = function(block) {
   var variables = Blockly.Variables.allUsedVarModels(workspace) || [];
   for (var i = 0, variable; variable = variables[i]; i++) {
     varName = variable.name;
-    if (block.arguments_.indexOf(varName) == -1) {
+    if (block.getVars().indexOf(varName) == -1) {
       globals.push(Blockly.PHP.variableDB_.getName(varName,
           Blockly.VARIABLE_CATEGORY_NAME));
     }
@@ -68,8 +68,9 @@ Blockly.PHP['procedures_defreturn'] = function(block) {
     returnValue = Blockly.PHP.INDENT + 'return ' + returnValue + ';\n';
   }
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
-    args[i] = Blockly.PHP.variableDB_.getName(block.arguments_[i],
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
+    args[i] = Blockly.PHP.variableDB_.getName(variables[i],
         Blockly.VARIABLE_CATEGORY_NAME);
   }
   var code = 'function ' + funcName + '(' + args.join(', ') + ') {\n' +
@@ -90,7 +91,8 @@ Blockly.PHP['procedures_callreturn'] = function(block) {
   var funcName = Blockly.PHP.variableDB_.getName(
       block.getFieldValue('NAME'), Blockly.PROCEDURE_CATEGORY_NAME);
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
     args[i] = Blockly.PHP.valueToCode(block, 'ARG' + i,
         Blockly.PHP.ORDER_COMMA) || 'null';
   }
diff --git a/generators/python/procedures.js b/generators/python/procedures.js
index 8cc05dd3a..521b5e4cc 100644
--- a/generators/python/procedures.js
+++ b/generators/python/procedures.js
@@ -25,7 +25,7 @@ Blockly.Python['procedures_defreturn'] = function(block) {
   var variables = Blockly.Variables.allUsedVarModels(workspace) || [];
   for (var i = 0, variable; variable = variables[i]; i++) {
     varName = variable.name;
-    if (block.arguments_.indexOf(varName) == -1) {
+    if (block.getVars().indexOf(varName) == -1) {
       globals.push(Blockly.Python.variableDB_.getName(varName,
           Blockly.VARIABLE_CATEGORY_NAME));
     }
@@ -71,8 +71,9 @@ Blockly.Python['procedures_defreturn'] = function(block) {
     branch = Blockly.Python.PASS;
   }
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
-    args[i] = Blockly.Python.variableDB_.getName(block.arguments_[i],
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
+    args[i] = Blockly.Python.variableDB_.getName(variables[i],
         Blockly.VARIABLE_CATEGORY_NAME);
   }
   var code = 'def ' + funcName + '(' + args.join(', ') + '):\n' +
@@ -93,7 +94,8 @@ Blockly.Python['procedures_callreturn'] = function(block) {
   var funcName = Blockly.Python.variableDB_.getName(block.getFieldValue('NAME'),
       Blockly.PROCEDURE_CATEGORY_NAME);
   var args = [];
-  for (var i = 0; i < block.arguments_.length; i++) {
+  var variables = block.getVars();
+  for (var i = 0; i < variables.length; i++) {
     args[i] = Blockly.Python.valueToCode(block, 'ARG' + i,
         Blockly.Python.ORDER_NONE) || 'None';
   }