diff --git a/lib/mixins/property-effects.html b/lib/mixins/property-effects.html
index 2321826b7e..4d92e7703b 100644
--- a/lib/mixins/property-effects.html
+++ b/lib/mixins/property-effects.html
@@ -189,7 +189,7 @@
     let changedProp = info.property;
     if (fn) {
       fn.call(inst, inst.__data[changedProp], oldProps[changedProp]);
-    } else {
+    } else if (!info.dynamicFn) {
       console.warn('observer method `' + info.methodName + '` not defined');
     }
   }
@@ -1905,7 +1905,7 @@
        * @protected
        */
       _createPropertyObserver(property, methodName, dynamicFn) {
-        let info = { property, methodName };
+        let info = { property, methodName, dynamicFn };
         this._addPropertyEffect(property, TYPES.OBSERVE, {
           fn: runObserverEffect, info, trigger: {name: property}
         });
@@ -2317,6 +2317,7 @@
             let dynamicFns = templateInfo.dynamicFns;
             if (dynamicFns && dynamicFns[methodName] || signature.static) {
               dependencies.push(methodName);
+              signature.dynamicFn = true;
             }
           } else {
             // Property or path
diff --git a/test/unit/property-effects.html b/test/unit/property-effects.html
index 1310ef0365..01761095e4 100644
--- a/test/unit/property-effects.html
+++ b/test/unit/property-effects.html
@@ -392,8 +392,13 @@
 
   var el;
 
+  setup(function() {
+    sinon.spy(console, 'warn');
+  });
+
   teardown(function() {
     document.body.removeChild(el);
+    console.warn.restore();
   });
 
   test('annotated computation with dynamic function', function() {
@@ -407,6 +412,7 @@
     };
 
     assert.equal(el.$.check.textContent, 'changed: Hello World.');
+    assert.equal(console.warn.callCount, 0);
   });
 
   test('annotated computation / late resolved dynamic function', function() {
@@ -420,6 +426,7 @@
     };
 
     assert.equal(el.$.check.textContent, 'translated: Hello');
+    assert.equal(console.warn.callCount, 0);
   });
 
   test('method observer with dynamic function', function() {
@@ -444,7 +451,7 @@
 
     el.translateMessage = sinon.spy();
     assert.equal(el.translateMessage.callCount, 1);
-
+    assert.equal(console.warn.callCount, 0);
   });
 
   test('observer with dynamic function', function() {
@@ -468,7 +475,7 @@
 
     el.messageChanged = sinon.spy();
     assert.equal(el.messageChanged.callCount, 1);
-
+    assert.equal(console.warn.callCount, 0);
   });
 
   test('computed property with dynamic function', function() {
@@ -497,7 +504,7 @@
 
     assert.equal(called, 1);
     assert.equal(el.computedValue, 'translated: Hello');
-
+    assert.equal(console.warn.callCount, 0);
   });
 
   test('ensure annotator can pass dynamic fn to parent props', function(done) {
@@ -507,6 +514,7 @@
     setTimeout(function() {
       var check = el.root.querySelector('p');
       assert.equal(check.textContent, 'text');
+      assert.equal(console.warn.callCount, 0);
       done();
     });