diff --git a/test/image_mock.hpp b/test/image_mock.hpp
index 8259aa9..c831c45 100644
--- a/test/image_mock.hpp
+++ b/test/image_mock.hpp
@@ -15,6 +15,7 @@
     MOCK_METHOD1(open, bool(const std::string&));
     MOCK_METHOD0(close, void());
     MOCK_METHOD2(write, bool(std::uint32_t, const std::vector<std::uint8_t>&));
+    MOCK_METHOD0(getSize, int());
 };
 
 } // namespace blobs