diff --git a/libwvdrmengine/cdm/core/test/crypto_session_unittest.cpp b/libwvdrmengine/cdm/core/test/crypto_session_unittest.cpp
index b42015da..96bba6af 100644
--- a/libwvdrmengine/cdm/core/test/crypto_session_unittest.cpp
+++ b/libwvdrmengine/cdm/core/test/crypto_session_unittest.cpp
@@ -5,6 +5,7 @@
 #include <memory>
 #include <string>
 
+#include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 #include "crypto_session.h"
@@ -19,6 +20,10 @@
 #include "wv_cdm_types.h"
 #include "wv_metrics.pb.h"
 
+using ::testing::AllOf;
+using ::testing::Ge;
+using ::testing::Le;
+
 namespace {
 
 const uint8_t kOemCert[] = {
@@ -296,7 +301,7 @@ TEST_F(CryptoSessionMetricsTest, OpenSessionValidMetrics) {
   // lite, convert these tests to use Message-based convenience functions.
 
   // Validate common metrics regardless of provisioning type.
-  EXPECT_EQ(1, metrics_proto.oemcrypto_initialize_time_us().size());
+  ASSERT_EQ(1, metrics_proto.oemcrypto_initialize_time_us().size());
   EXPECT_TRUE(metrics_proto.oemcrypto_initialize_time_us(0)
                   .attributes()
                   .has_oem_crypto_result());
@@ -327,7 +332,8 @@ TEST_F(CryptoSessionMetricsTest, OpenSessionValidMetrics) {
     EXPECT_EQ(OEMCrypto_OEMCertificate,
               metrics_proto.oemcrypto_provisioning_method().int_value());
     ASSERT_EQ(1, metrics_proto.oemcrypto_get_oem_public_certificate().size());
-    EXPECT_EQ(1, metrics_proto.oemcrypto_get_oem_public_certificate(0).count());
+    EXPECT_THAT(metrics_proto.oemcrypto_get_oem_public_certificate(0).count(),
+                AllOf(Ge(1), Le(2)));
   } else if (token_type == kClientTokenDrmCert) {
     // TODO(blueeyes): Add support for getting the system id from a
     // pre-installed DRM certificate..
@@ -373,8 +379,9 @@ TEST_F(CryptoSessionMetricsTest, GetProvisioningTokenValidMetrics) {
 
     EXPECT_EQ(OEMCrypto_OEMCertificate,
               metrics_proto.oemcrypto_provisioning_method().int_value());
-    EXPECT_EQ(1, metrics_proto.oemcrypto_get_oem_public_certificate().size());
-    EXPECT_EQ(1, metrics_proto.oemcrypto_get_oem_public_certificate(0).count());
+    ASSERT_EQ(1, metrics_proto.oemcrypto_get_oem_public_certificate().size());
+    EXPECT_THAT(metrics_proto.oemcrypto_get_oem_public_certificate(0).count(),
+                AllOf(Ge(1), Le(2)));
 
     ASSERT_EQ(1, metrics_proto.crypto_session_get_token().size());
     EXPECT_EQ(1, metrics_proto.crypto_session_get_token(0).count());
diff --git a/libwvdrmengine/cdm/util/test/test_sleep.cpp b/libwvdrmengine/cdm/util/test/test_sleep.cpp
index 1656381a..4893ca74 100644
--- a/libwvdrmengine/cdm/util/test/test_sleep.cpp
+++ b/libwvdrmengine/cdm/util/test/test_sleep.cpp
@@ -23,7 +23,7 @@ namespace wvcdm {
 
 bool TestSleep::real_sleep_ = true;
 TestSleep::CallBack* TestSleep::callback_ = nullptr;
-int TestSleep::total_clock_rollback_ = 0;
+int TestSleep::total_clock_rollback_seconds_ = 0;
 
 void TestSleep::Sleep(unsigned int seconds) {
   int64_t milliseconds = 1000 * seconds;
@@ -33,11 +33,15 @@ void TestSleep::Sleep(unsigned int seconds) {
     // total since the start, and then compare to a running total of sleep
     // calls. We sleep for approximately x second, and then advance the clock by
     // the amount of time that has actually passed.
-    static auto start_real = std::chrono::system_clock().now();
-    static int64_t fake_clock = 0;
+    static const auto start_real = std::chrono::system_clock().now();
     sleep(seconds);
-    auto now_real = std::chrono::system_clock().now();
-    int64_t total_real = (now_real - start_real) / std::chrono::milliseconds(1);
+    const auto now_real = std::chrono::system_clock().now();
+    const int64_t rollback_adjustment = 1000 * total_clock_rollback_seconds_;
+    const int64_t total_real =
+        (now_real - start_real) / std::chrono::milliseconds(1) +
+        rollback_adjustment;
+
+    static int64_t fake_clock = 0;
     // We want to advance the fake clock by the difference between the real
     // clock, and the previous value on the fake clock.
     milliseconds = total_real - fake_clock;
@@ -90,7 +94,7 @@ bool TestSleep::RollbackSystemTime(int seconds) {
 
   // For both real and fake sleep we still update the callback and we still keep
   // track of the total amount of time slept.
-  total_clock_rollback_ += seconds;
+  total_clock_rollback_seconds_ += seconds;
   if (callback_ != nullptr) callback_->ElapseTime(-1000 * seconds);
   return true;
 }
@@ -98,7 +102,6 @@ bool TestSleep::RollbackSystemTime(int seconds) {
 bool TestSleep::CanChangeSystemTime() {
   // If we are using a fake clock, then we can move the clock backwards by
   // just going backwards.
-  // ElapseTime.
   if (!real_sleep_) {
     return true;
   }
diff --git a/libwvdrmengine/cdm/util/test/test_sleep.h b/libwvdrmengine/cdm/util/test/test_sleep.h
index 34c4b3f6..35dcdc70 100644
--- a/libwvdrmengine/cdm/util/test/test_sleep.h
+++ b/libwvdrmengine/cdm/util/test/test_sleep.h
@@ -44,8 +44,8 @@ class TestSleep {
   // Roll the system clock forward to undo all previous calls to
   // RollBackSystemTime. Returns true on success.
   static bool ResetRollback() {
-    return total_clock_rollback_ == 0 ||
-           RollbackSystemTime(-total_clock_rollback_);
+    return total_clock_rollback_seconds_ == 0 ||
+           RollbackSystemTime(-total_clock_rollback_seconds_);
   }
 
   // Returns true if the system time can be rolled back. This is true on some
@@ -67,7 +67,7 @@ class TestSleep {
   static CallBack* callback_;
   // The sum of all calls to RollBackSystemTime. Kept so we can undo all changes
   // at the end of a test.
-  static int total_clock_rollback_;
+  static int total_clock_rollback_seconds_;
 };
 
 }  // namespace wvcdm