diff --git a/com.archimatetool.model/src/com/archimatetool/model/impl/Feature.java b/com.archimatetool.model/src/com/archimatetool/model/impl/Feature.java
index 8ad51cf84..c4946850d 100644
--- a/com.archimatetool.model/src/com/archimatetool/model/impl/Feature.java
+++ b/com.archimatetool.model/src/com/archimatetool/model/impl/Feature.java
@@ -220,5 +220,20 @@ public String toString() {
         result.append(')');
         return result.toString();
     }
+    
+    /**
+     * Over-ride this to test equality based on this Feature's name
+     * This ensures we have unique entries keyed by name
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if(this == obj) {
+            return true;
+        }
+        
+        return (obj instanceof Feature) &&
+                name != null &&
+                name.equals(((Feature)obj).name);
+    }
 
 } //Feature
diff --git a/com.archimatetool.model/src/com/archimatetool/model/impl/FeaturesEList.java b/com.archimatetool.model/src/com/archimatetool/model/impl/FeaturesEList.java
index 80da81696..84741e735 100644
--- a/com.archimatetool.model/src/com/archimatetool/model/impl/FeaturesEList.java
+++ b/com.archimatetool.model/src/com/archimatetool/model/impl/FeaturesEList.java
@@ -35,12 +35,6 @@ public IFeature putString(String name, String value, String defaultValue) {
         
         IFeature feature = getFeature(name);
 
-        // Value equals default value so remove it
-        if(value.equals(defaultValue)) {
-            remove(name);
-            return feature;
-        }
-        
         // New one
         if(feature == null) {
             feature = IArchimateFactory.eINSTANCE.createFeature();
@@ -48,7 +42,11 @@ public IFeature putString(String name, String value, String defaultValue) {
             feature.setValue(value);
             add(feature);
         }
-        // Different
+        // Value equals default value so remove it
+        else if(value.equals(defaultValue)) {
+            remove(feature);
+        }
+        // Different value
         else if(!value.equals(feature.getValue())) {
             feature.setValue(value);
         }
@@ -134,4 +132,13 @@ private void checkNull(String s) {
             throw new IllegalArgumentException("key or value cannot be null"); //$NON-NLS-1$
         }
     }
+    
+    /**
+     * Return true so that {@link #contains(Object)} checks {@link Feature#equals(Object)}
+     * For unique entries keyed by name
+     */
+    @Override
+    protected boolean useEquals() {
+        return true;
+    }
 }
diff --git a/tests/com.archimatetool.model.tests/src/com/archimatetool/model/impl/FeaturesEListTests.java b/tests/com.archimatetool.model.tests/src/com/archimatetool/model/impl/FeaturesEListTests.java
index 6b6305660..930d9cf0e 100644
--- a/tests/com.archimatetool.model.tests/src/com/archimatetool/model/impl/FeaturesEListTests.java
+++ b/tests/com.archimatetool.model.tests/src/com/archimatetool/model/impl/FeaturesEListTests.java
@@ -162,4 +162,92 @@ public void getFeature() {
         
         assertNull(list.getFeature("bogus"));
     }
+    
+    @Test
+    public void noDuplicateFeature1() {
+        IFeature feature = IArchimateFactory.eINSTANCE.createFeature();
+        feature.setName("uniqueName");
+        feature.setValue("someValue");
+        
+        // Add the feature
+        boolean result = list.add(feature);
+        assertTrue(result);
+        
+        // Should not be able to add the first feature again
+        result = list.add(feature);
+        assertFalse(result);
+
+        // Should not be able to add the first feature again, even if name and value change
+        feature.setName("uniqueName2");
+        feature.setValue("someValue2");
+        result = list.add(feature);
+        assertFalse(result);
+    }
+    
+    @Test
+    public void noDuplicateFeature2() {
+        IFeature feature = IArchimateFactory.eINSTANCE.createFeature();
+        feature.setName("uniqueName");
+        feature.setValue("someValue");
+        
+        // Add the feature
+        boolean result = list.add(feature);
+        assertTrue(result);
+        
+        // Should not be able to add a different feature object with the same name
+        IFeature feature2 = IArchimateFactory.eINSTANCE.createFeature();
+        feature2.setName("uniqueName");
+        feature2.setValue("someValue2");
+        result = list.add(feature2);
+        assertFalse(result);
+    }
+
+    @Test
+    public void noDuplicateFeature3() {
+        IFeature feature = IArchimateFactory.eINSTANCE.createFeature();
+        feature.setName("uniqueName");
+        feature.setValue("someValue");
+        
+        // Add the feature
+        boolean result = list.add(feature);
+        assertTrue(result);
+        
+        // Should be able to add a different feature object with a different name
+        IFeature feature2 = IArchimateFactory.eINSTANCE.createFeature();
+        feature2.setName("uniqueName2");
+        feature2.setValue("someValue2");
+        result = list.add(feature2);
+        assertTrue(result);
+    }
+    
+    @Test
+    public void noDuplicateFeature4() {
+        // Create another list
+        IArchimateElement element = IArchimateFactory.eINSTANCE.createArtifact();
+        FeaturesEList list2 = new FeaturesEList(IFeature.class, (InternalEObject)element, IArchimatePackage.ARCHIMATE_CONCEPT__FEATURES);
+
+        // Add Feature to first list
+        IFeature feature1 = IArchimateFactory.eINSTANCE.createFeature();
+        feature1.setName("uniqueName");
+        feature1.setValue("someValue");
+        list.add(feature1);
+        
+        // Add feature with same name to second list
+        IFeature feature2 = IArchimateFactory.eINSTANCE.createFeature();
+        feature2.setName("uniqueName");
+        feature2.setValue("someValue");
+        list2.add(feature2);
+
+        // Should not be able to add first list to second list
+        boolean result = list2.addAll(list);
+        assertFalse(result);
+        
+        // remove it
+        list2.remove(feature2);
+        
+        // Should be able to add it now
+        result = list2.addAll(list);
+        assertTrue(result);
+    }
+
 }