diff --git a/src/Collapse.js b/src/Collapse.js
index 9bac27e6d..af2146d20 100644
--- a/src/Collapse.js
+++ b/src/Collapse.js
@@ -127,6 +127,7 @@ class Collapse extends Component {
               style={{ ...childProps.style, ...style }}
               className={classes}
               ref={this.props.innerRef}
+              aria-expanded={isOpen ? 'true' : 'false'}
             >
               {children}
             </Tag>
diff --git a/src/UncontrolledCollapse.js b/src/UncontrolledCollapse.js
index c5c77a9a9..b893e7b08 100644
--- a/src/UncontrolledCollapse.js
+++ b/src/UncontrolledCollapse.js
@@ -49,7 +49,7 @@ class UncontrolledCollapse extends Component {
   }
 
   render() {
-    return <Collapse isOpen={this.state.isOpen} {...omit(this.props, omitKeys)} />;
+    return <Collapse isOpen={this.state.isOpen} {...omit(this.props, omitKeys)} aria-expanded={this.state.isOpen ? 'true' : 'false'} />;
   }
 }
 
diff --git a/src/__tests__/Collapse.spec.js b/src/__tests__/Collapse.spec.js
index 3000ffad9..bc508860f 100644
--- a/src/__tests__/Collapse.spec.js
+++ b/src/__tests__/Collapse.spec.js
@@ -122,4 +122,12 @@ describe('Collapse', () => {
     expect(wrapper.state('height')).toBe(null);
     wrapper.unmount();
   });
+
+  it('should set aria-expanded', () => {
+    isOpen = false;
+    wrapper = mount(<Collapse isOpen={isOpen} />);
+    expect(wrapper.find('div').prop('aria-expanded')).toBe('false');
+    toggle();
+    expect(wrapper.find('div').prop('aria-expanded')).toBe('true');
+  });
 });
diff --git a/src/__tests__/UncontrolledCollapse.spec.js b/src/__tests__/UncontrolledCollapse.spec.js
index dcd5e102f..9e6e721a3 100644
--- a/src/__tests__/UncontrolledCollapse.spec.js
+++ b/src/__tests__/UncontrolledCollapse.spec.js
@@ -95,4 +95,14 @@ describe('UncontrolledCollapse', () => {
 
     expect(UncontrolledCollapse.prototype.toggle.mock.calls.length).toBe(1);
   });
+
+  it('should set aria-expanded', () => {
+    const collapse = shallow(<UncontrolledCollapse toggler="#toggler">Yo!</UncontrolledCollapse>);
+
+    expect(collapse.prop('aria-expanded')).toBe('false');
+    toggler.click();
+    collapse.update();
+
+    expect(collapse.prop('aria-expanded')).toBe('true');
+  });
 });