# System.Collections.Generic

``` diff
 namespace System.Collections.Generic {
-    public interface IDictionary<TKey, TValue> : ICollection<KeyValuePair<TKey, TValue>>, IEnumerable, IEnumerable<KeyValuePair<TKey, TValue>>
+    public interface IDictionary<TKey, TValue> : ICollection<KeyValuePair<TKey, TValue>>, IEnumerable, IEnumerable<KeyValuePair<TKey, TValue>> where TKey : object
-    public interface IReadOnlyDictionary<TKey, TValue> : IEnumerable, IEnumerable<KeyValuePair<TKey, TValue>>, IReadOnlyCollection<KeyValuePair<TKey, TValue>>
+    public interface IReadOnlyDictionary<TKey, TValue> : IEnumerable, IEnumerable<KeyValuePair<TKey, TValue>>, IReadOnlyCollection<KeyValuePair<TKey, TValue>> where TKey : object
 }
```

