diff --git a/test/mock/test-mock.cpp b/test/mock/test-mock.cpp
index b7d7563..b8e89ad 100644
--- a/test/mock/test-mock.cpp
+++ b/test/mock/test-mock.cpp
@@ -55,22 +55,6 @@ template <typename... T> struct promise {
   bool is_canceled() const noexcept { return false; }
 };
 
-template <typename... T> struct promise {
-  void set_value(T...) noexcept {}
-
-  void operator()(T...) && noexcept {}
-
-  void set_exception(std::exception_ptr exception) noexcept {
-    // ...
-    (void)exception;
-  }
-
-  void set_error(std::error_code error) noexcept {
-    // ...
-    (void)error;
-  }
-};
-
 template <typename... Result> struct accumulator {
   auto accumulate() {
     return [] {};