diff --git a/can-define.js b/can-define.js
index eccd334..1c4796f 100644
--- a/can-define.js
+++ b/can-define.js
@@ -230,7 +230,7 @@ define.property = function(objPrototype, prop, definition, dataInitializers, com
 
 		// If value is an object or array, give a warning 
 		if (definition.value !== null && typeof definition.value === 'object') {
-			dev.warn("The value for options is set to an object. This will be shared by all instances of the DefineMap. Use a function that returns the object instead.");
+			dev.warn("can-define: The value for options is set to an object. This will be shared by all instances of the DefineMap. Use a function that returns the object instead.");
 		}
 		//!steal-remove-end
 		getInitialValue = Observation.ignore(make.get.defaultValue(prop, definition, typeConvert, eventsSetter));
diff --git a/map/map-test.js b/map/map-test.js
index 6fc1273..a01d2cf 100644
--- a/map/map-test.js
+++ b/map/map-test.js
@@ -843,7 +843,7 @@ if(System.env.indexOf("production") < 0) {
 		QUnit.expect(2);
 		var oldwarn = canDev.warn;
 		canDev.warn = function(mesg) {
-			QUnit.equal(mesg, "The value for options is set to an object. This will be shared by all instances of the DefineMap. Use a function that returns the object instead.", "Warning is expected message");
+			QUnit.equal(mesg, "can-define: The value for options is set to an object. This will be shared by all instances of the DefineMap. Use a function that returns the object instead.");
 		};
 		//should issue a warning
 		DefineMap.extend({