diff --git a/http_comms/comms.go b/http_comms/comms.go
index 879d173bbac..4983c1f2678 100644
--- a/http_comms/comms.go
+++ b/http_comms/comms.go
@@ -926,11 +926,11 @@ func NewHTTPCommunicator(
 		logger:     logger,
 		clock:      clock,
 	}
-	
+
 	// Shuffle the list of URLs so that if a server goes down,
 	// clients will be distributed better accross
 	// the remaining servers.
-	rand.Seed(time.Now().UnixNano())
+	rand.Seed(utils.GetTime().Now().UnixNano())
 	rand.Shuffle(len(urls), func(i, j int) {
 		urls[i], urls[j] = urls[j], urls[i]
 	})
diff --git a/http_comms/comms_test.go b/http_comms/comms_test.go
index 54e7f10eeb4..e04fab710b7 100644
--- a/http_comms/comms_test.go
+++ b/http_comms/comms_test.go
@@ -228,9 +228,12 @@ func (self *CommsTestSuite) TestAbort() {
 
 func (self *CommsTestSuite) TestEnrollment() {
 	urls := []string{self.frontend1.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -266,9 +269,12 @@ func (self *CommsTestSuite) TestEnrollment() {
 
 func (self *CommsTestSuite) TestServerError() {
 	urls := []string{self.frontend1.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -315,9 +321,12 @@ func (self *CommsTestSuite) TestServerError() {
 // 500, Frontend2 is down too.
 func (self *CommsTestSuite) TestMultiFrontends() {
 	urls := []string{self.frontend1.URL, self.frontend2.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -377,9 +386,12 @@ func (self *CommsTestSuite) TestMultiFrontends() {
 // Client configured with two frontends. Both keep failing.
 func (self *CommsTestSuite) TestMultiFrontendsAllIsBorked() {
 	urls := []string{self.frontend1.URL, self.frontend2.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -452,9 +464,12 @@ func (self *CommsTestSuite) TestMultiFrontendsAllIsBorked() {
 // switching to FE2
 func (self *CommsTestSuite) TestMultiFrontendsIntermittantFailure() {
 	urls := []string{self.frontend1.URL, self.frontend2.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -513,9 +528,12 @@ func (self *CommsTestSuite) TestMultiFrontendsIntermittantFailure() {
 // fails we switch back to FE1.
 func (self *CommsTestSuite) TestMultiFrontendsHeavyFailure() {
 	urls := []string{self.frontend1.URL, self.frontend2.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -588,9 +606,12 @@ func (self *CommsTestSuite) TestMultiFrontendsHeavyFailure() {
 func (self *CommsTestSuite) TestMultiFrontendRedirect() {
 	// FE2 is not known to the client in advance.
 	urls := []string{self.frontend1.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -655,10 +676,14 @@ func (self *CommsTestSuite) TestMultiFrontendRedirect() {
 
 // Check that redirects do not cause un-neccesary sleeps.
 func (self *CommsTestSuite) TestMultiFrontendRedirectWithErrors() {
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
+
 	urls := []string{self.frontend1.URL}
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -751,9 +776,12 @@ func (self *CommsTestSuite) TestMultiFrontendRedirectWithErrors() {
 // Frontends redirecting to each other.
 func (self *CommsTestSuite) TestMultiRedirects() {
 	urls := []string{self.frontend1.URL}
+	mock_clock := utils.NewMockClock(time.Unix(100, 0))
+	cancel := utils.MockTime(mock_clock)
+	defer cancel()
 
 	clock := &FakeClock{
-		MockClock: utils.NewMockClock(time.Unix(100, 0)),
+		MockClock: mock_clock,
 		events:    &self.frontend1.events}
 
 	ctx, cancel := context.WithCancel(context.Background())