diff --git a/lib/__tests__/index-test.js b/lib/__tests__/index-test.js
index 76d1c9e..5a1be9e 100644
--- a/lib/__tests__/index-test.js
+++ b/lib/__tests__/index-test.js
@@ -35,6 +35,18 @@ describe('props', () => {
         });
       });
 
+      it('does not warn if onClick is null', () => {
+        doNotExpectWarning(assertions.props.onClick.NO_LABEL.msg, () => {
+          <div onClick={null}/>;
+        });
+      });
+
+      it('does not warn if onClick is undefined', () => {
+        doNotExpectWarning(assertions.props.onClick.NO_LABEL.msg, () => {
+          <div onClick={undefined}/>;
+        });
+      });
+
       it('does not warn if there is an aria-label', () => {
         doNotExpectWarning(assertions.props.onClick.NO_LABEL.msg, () => {
           <div aria-label="foo" onClick={k}/>;
diff --git a/lib/index.js b/lib/index.js
index f1e136b..8ca8432 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -12,6 +12,7 @@ var assertAccessibility = (tagName, props, children) => {
 
   var propTests;
   for (var propName in props) {
+    if (props[propName] === null || props[propName] === undefined) continue;
     propTests = assertions.props[propName] || [];
     for (key in propTests)
       if (propTests[key] && !propTests[key].test(tagName, props, children))