diff --git a/integrationtests/handshake/rtt.go b/integrationtests/handshake/rtt.go
index 5d8b88816..fe125eb11 100644
--- a/integrationtests/handshake/rtt.go
+++ b/integrationtests/handshake/rtt.go
@@ -58,7 +58,7 @@ var _ = Describe("Handshake integration tets", func() {
 	}
 
 	expectDurationInRTTs := func(num int) {
-		testDuration := time.Now().Sub(testStartedAt)
+		testDuration := time.Since(testStartedAt)
 		expectedDuration := time.Duration(num) * rtt
 		Expect(testDuration).To(SatisfyAll(
 			BeNumerically(">=", expectedDuration),
diff --git a/session_test.go b/session_test.go
index 01aa02ccd..7265504b0 100644
--- a/session_test.go
+++ b/session_test.go
@@ -906,7 +906,7 @@ var _ = Describe("Session", func() {
 			err := sess.sendPublicReset(1)
 			Expect(err).NotTo(HaveOccurred())
 			Expect(mconn.written).To(HaveLen(1))
-			Expect(mconn.written[0]).To(ContainSubstring(string([]byte("PRST"))))
+			Expect(mconn.written[0]).To(ContainSubstring("PRST"))
 		})
 
 		It("informs the SentPacketHandler about sent packets", func() {
@@ -1317,7 +1317,7 @@ var _ = Describe("Session", func() {
 			time.Sleep(10 * time.Millisecond) // wait for the run loop to spin up
 			sess.scheduleSending()            // wake up the run loop
 			Eventually(func() [][]byte { return mconn.written }).Should(HaveLen(1))
-			Expect(mconn.written[0]).To(ContainSubstring(string([]byte("PRST"))))
+			Expect(mconn.written[0]).To(ContainSubstring("PRST"))
 			Eventually(sess.runClosed).Should(BeClosed())
 		})