Fix compiler warnings
diff --git a/tensorflow/core/kernels/data/take_dataset_op.h b/tensorflow/core/kernels/data/take_dataset_op.h
index 9800fba..ac7ef5b 100644
--- a/tensorflow/core/kernels/data/take_dataset_op.h
+++ b/tensorflow/core/kernels/data/take_dataset_op.h
@@ -32,13 +32,13 @@
   std::unique_ptr<IteratorBase> MakeIteratorInternal(
       const string& prefix) const override;
 
-  const DataTypeVector& output_dtypes() const;
+  const DataTypeVector& output_dtypes() const override;
 
-  const std::vector<PartialTensorShape>& output_shapes() const;
+  const std::vector<PartialTensorShape>& output_shapes() const override;
 
-  string DebugString() const;
+  string DebugString() const override;
 
-  int64 Cardinality() const;
+  int64 Cardinality() const override;
 
   bool IsStateful() const override;