diff --git a/core/field_angle.js b/core/field_angle.js
index 9793248d0..ac3404f1a 100644
--- a/core/field_angle.js
+++ b/core/field_angle.js
@@ -77,7 +77,7 @@ Blockly.FieldAngle.prototype.setChangeHandler = function(handler) {
   } else {
     wrappedHandler = Blockly.FieldAngle.angleValidator;
   }
-  Blockly.FieldAngle.superClass_.setChangeHandler(wrappedHandler);
+  Blockly.FieldAngle.superClass_.setChangeHandler.call(this, wrappedHandler);
 };
 
 /**
diff --git a/core/field_variable.js b/core/field_variable.js
index 44f5e1663..a03cfe6ec 100644
--- a/core/field_variable.js
+++ b/core/field_variable.js
@@ -75,7 +75,7 @@ Blockly.FieldVariable.prototype.setChangeHandler = function(handler) {
   } else {
     wrappedHandler = Blockly.FieldVariable.dropdownChange;
   }
-  Blockly.FieldVariable.superClass_.setChangeHandler(wrappedHandler);
+  Blockly.FieldVariable.superClass_.setChangeHandler.call(this, wrappedHandler);
 };
 
 /**