diff --git a/testing/common/SystemControlReport.cpp b/testing/common/SystemControlReport.cpp
index d2e54dac..9111259f 100644
--- a/testing/common/SystemControlReport.cpp
+++ b/testing/common/SystemControlReport.cpp
@@ -25,6 +25,7 @@ SystemControlReport::SystemControlReport(const void* data) {
   const ReportData& report_data =
     *static_cast<const ReportData*>(data);
   memcpy(&report_data_, &report_data, sizeof(report_data_));
+  this->push_back(report_data_.key);
 }
 
 uint8_t SystemControlReport::Key() const {
diff --git a/testing/common/SystemControlReport.h b/testing/common/SystemControlReport.h
index e9623ae9..b96c07c6 100644
--- a/testing/common/SystemControlReport.h
+++ b/testing/common/SystemControlReport.h
@@ -24,7 +24,7 @@
 namespace kaleidoscope {
 namespace testing {
 
-class SystemControlReport {
+class SystemControlReport : public std::vector<uint8_t> {
  public:
   typedef HID_SystemControlReport_Data_t ReportData;
 
diff --git a/testing/common/matchers.h b/testing/common/matchers.h
index cfaad182..f521bb35 100644
--- a/testing/common/matchers.h
+++ b/testing/common/matchers.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include "kaleidoscope/key_defs.h"
+#include "testing/common/SystemControlReport.h"
 
 // Out of order because `fix-macros.h` clears the preprocessor environment for
 // gtest and gmock.
@@ -26,6 +27,31 @@
 namespace kaleidoscope {
 namespace testing {
 
+MATCHER_P(Contains, key, negation ? "does not contain" : "contains") {
+  return arg.Key() == key.getKeyCode();
+}
+
+class SystemControlReportIsNullMatcher
+    : public ::testing::MatcherInterface<SystemControlReport> {
+ public:
+  bool MatchAndExplain(SystemControlReport report,
+                       ::testing::MatchResultListener* /* ignored */) const override {
+    return report.Key() == 0;
+  }
+
+  void DescribeTo(std::ostream* os) const override {
+    *os << "is empty";
+  }
+
+  void DescribeNegationTo(std::ostream* os) const override {
+    *os << "is not empty";
+  }
+};
+
+::testing::Matcher<SystemControlReport> IsNull() {
+  return ::testing::MakeMatcher(new SystemControlReportIsNullMatcher);
+}
+
 auto Contains(Key key) { return ::testing::Contains(key.getKeyCode()); }
 
 }  // namespace testing
diff --git a/testing/issue_840/test/simulator_test.cpp b/testing/issue_840/test/simulator_test.cpp
index 0820bccd..b479b5e3 100644
--- a/testing/issue_840/test/simulator_test.cpp
+++ b/testing/issue_840/test/simulator_test.cpp
@@ -42,30 +42,24 @@ TEST_F(Issue840, HasNotRegressed) {
   auto state = RunCycle();
 
   ASSERT_EQ(state->SystemControlReports().size(), 1);
-  EXPECT_EQ(
-      state->SystemControlReports(0).Key(),
-      System_PowerDown.getKeyCode());
+  EXPECT_THAT(state->SystemControlReports(0), Contains(System_PowerDown));
 
   sim_.Press(3, 5); // Press System_Sleep
   state = RunCycle();
 
   ASSERT_EQ(state->SystemControlReports().size(), 1);
-  EXPECT_EQ(
-      state->SystemControlReports(0).Key(),
-      System_Sleep.getKeyCode());
+  EXPECT_THAT(state->SystemControlReports(0), Contains(System_Sleep));
 
   sim_.Release(2, 1);  // Release System_PowerDown
   state = RunCycle();
 
-  ASSERT_EQ(state->SystemControlReports().size(), 0);
+  EXPECT_EQ(state->SystemControlReports().size(), 0);
 
   sim_.Release(3, 5);  // Release System_Sleep
   state = RunCycle();
 
   ASSERT_EQ(state->SystemControlReports().size(), 1);
-  EXPECT_EQ(
-      state->SystemControlReports(0).Key(),
-      0 /* null report */);
+  EXPECT_THAT(state->SystemControlReports(0), IsNull());
 
   state = RunCycle();
 
@@ -77,33 +71,25 @@ TEST_F(Issue840, HasNotRegressed) {
 //   auto state = RunCycle();
 // 
 //   ASSERT_EQ(state->SystemControlReports().size(), 1);
-//   EXPECT_EQ(
-//       state->SystemControlReports(0).Key(),
-//       System_PowerDown.getKeyCode());
+//   EXPECT_THAT(state->SystemControlReports(0), Contains(System_PowerDown));
 // 
 //   sim_.Press(3, 5); // Press System_Sleep
 //   state = RunCycle();
 // 
 //   ASSERT_EQ(state->SystemControlReports().size(), 1);
-//   EXPECT_EQ(
-//       state->SystemControlReports(0).Key(),
-//       System_Sleep.getKeyCode());
+//   EXPECT_THAT(state->SystemControlReports(0), Contains(System_Sleep));
 // 
 //   sim_.Release(2, 1);  // Release System_PowerDown
 //   state = RunCycle();
 // 
 //   ASSERT_EQ(state->SystemControlReports().size(), 1);
-//   EXPECT_EQ(
-//       state->SystemControlReports(0).Key(),
-//       0 /* null report */);
+//   EXPECT_THAT(state->SystemControlReports(0), IsNull());
 // 
 //   sim_.Release(3, 5);  // Release System_Sleep
 //   state = RunCycle();
 // 
 //   ASSERT_EQ(state->SystemControlReports().size(), 1);
-//   EXPECT_EQ(
-//       state->SystemControlReports(0).Key(),
-//       0 /* null report */);
+//   EXPECT_THAT(state->SystemControlReports(0), IsNull());
 // 
 //   state = RunCycle();
 //