diff --git a/phosphor-power-supply/test/mock.hpp b/phosphor-power-supply/test/mock.hpp
index 1235c01..13d22e6 100644
--- a/phosphor-power-supply/test/mock.hpp
+++ b/phosphor-power-supply/test/mock.hpp
@@ -69,6 +69,8 @@
   public:
     MOCK_METHOD(int, read, (), (override));
     MOCK_METHOD(void, write, (int value, std::bitset<32> flags), (override));
+    MOCK_METHOD(void, toggleLowHigh, (const std::chrono::milliseconds& delay),
+                (override));
     MOCK_METHOD(std::string, getName, (), (const, override));
 };