diff --git a/pbkdf2_test.go b/pbkdf2_test.go
index 0ae0c007..b61a0afa 100644
--- a/pbkdf2_test.go
+++ b/pbkdf2_test.go
@@ -34,10 +34,14 @@ type pbkdf2Suite struct{}
 var _ = Suite(&pbkdf2Suite{})
 
 func (s *pbkdf2Suite) TestKDFParamsDefault(c *C) {
+	var expectedTime int
 	restore := MockPBKDF2Benchmark(func(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) {
 		c.Check(targetDuration, Equals, 2*time.Second)
 		c.Check(hashAlg, Equals, crypto.SHA256)
-		return pbkdf2.Benchmark(targetDuration, hashAlg)
+		iter, err := pbkdf2.Benchmark(targetDuration, hashAlg)
+		c.Check(err, IsNil)
+		expectedTime = int(iter)
+		return iter, err
 	})
 	defer restore()
 
@@ -45,16 +49,21 @@ func (s *pbkdf2Suite) TestKDFParamsDefault(c *C) {
 	params, err := opts.KdfParams(32)
 	c.Assert(err, IsNil)
 	c.Check(params.Type, Equals, "pbkdf2")
+	c.Check(params.Time, Equals, expectedTime)
 	c.Check(params.Hash, Equals, HashAlg(crypto.SHA256))
 	c.Check(params.Memory, Equals, 0)
 	c.Check(params.CPUs, Equals, 0)
 }
 
 func (s *pbkdf2Suite) TestKDFParamsDefault48(c *C) {
+	var expectedTime int
 	restore := MockPBKDF2Benchmark(func(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) {
 		c.Check(targetDuration, Equals, 2*time.Second)
 		c.Check(hashAlg, Equals, crypto.SHA384)
-		return pbkdf2.Benchmark(targetDuration, hashAlg)
+		iter, err := pbkdf2.Benchmark(targetDuration, hashAlg)
+		c.Check(err, IsNil)
+		expectedTime = int(iter)
+		return iter, err
 	})
 	defer restore()
 
@@ -62,16 +71,21 @@ func (s *pbkdf2Suite) TestKDFParamsDefault48(c *C) {
 	params, err := opts.KdfParams(48)
 	c.Assert(err, IsNil)
 	c.Check(params.Type, Equals, "pbkdf2")
+	c.Check(params.Time, Equals, expectedTime)
 	c.Check(params.Hash, Equals, HashAlg(crypto.SHA384))
 	c.Check(params.Memory, Equals, 0)
 	c.Check(params.CPUs, Equals, 0)
 }
 
 func (s *pbkdf2Suite) TestKDFParamsDefault64(c *C) {
+	var expectedTime int
 	restore := MockPBKDF2Benchmark(func(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) {
 		c.Check(targetDuration, Equals, 2*time.Second)
 		c.Check(hashAlg, Equals, crypto.SHA512)
-		return pbkdf2.Benchmark(targetDuration, hashAlg)
+		iter, err := pbkdf2.Benchmark(targetDuration, hashAlg)
+		c.Check(err, IsNil)
+		expectedTime = int(iter)
+		return iter, err
 	})
 	defer restore()
 
@@ -79,20 +93,21 @@ func (s *pbkdf2Suite) TestKDFParamsDefault64(c *C) {
 	params, err := opts.KdfParams(64)
 	c.Assert(err, IsNil)
 	c.Check(params.Type, Equals, "pbkdf2")
+	c.Check(params.Time, Equals, expectedTime)
 	c.Check(params.Hash, Equals, HashAlg(crypto.SHA512))
 	c.Check(params.Memory, Equals, 0)
 	c.Check(params.CPUs, Equals, 0)
 }
 
 func (s *pbkdf2Suite) TestKDFParamsTargetDuration(c *C) {
+	var expectedTime int
 	restore := MockPBKDF2Benchmark(func(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) {
-		c.Logf("benchmarking (%d)", targetDuration)
-		if targetDuration != 200*time.Millisecond {
-			panic("")
-		}
 		c.Check(targetDuration, Equals, 200*time.Millisecond)
 		c.Check(hashAlg, Equals, crypto.SHA256)
-		return pbkdf2.Benchmark(targetDuration, hashAlg)
+		iter, err := pbkdf2.Benchmark(targetDuration, hashAlg)
+		c.Check(err, IsNil)
+		expectedTime = int(iter)
+		return iter, err
 	})
 	defer restore()
 
@@ -101,6 +116,7 @@ func (s *pbkdf2Suite) TestKDFParamsTargetDuration(c *C) {
 	params, err := opts.KdfParams(32)
 	c.Assert(err, IsNil)
 	c.Check(params.Type, Equals, "pbkdf2")
+	c.Check(params.Time, Equals, expectedTime)
 	c.Check(params.Hash, Equals, HashAlg(crypto.SHA256))
 	c.Check(params.Memory, Equals, 0)
 	c.Check(params.CPUs, Equals, 0)
@@ -119,10 +135,14 @@ func (s *pbkdf2Suite) TestKDFParamsForceIterations(c *C) {
 }
 
 func (s *pbkdf2Suite) TestKDFParamsCustomHash(c *C) {
+	var expectedTime int
 	restore := MockPBKDF2Benchmark(func(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) {
 		c.Check(targetDuration, Equals, 2*time.Second)
 		c.Check(hashAlg, Equals, crypto.SHA512)
-		return pbkdf2.Benchmark(targetDuration, hashAlg)
+		iter, err := pbkdf2.Benchmark(targetDuration, hashAlg)
+		c.Check(err, IsNil)
+		expectedTime = int(iter)
+		return iter, err
 	})
 	defer restore()
 
@@ -131,6 +151,7 @@ func (s *pbkdf2Suite) TestKDFParamsCustomHash(c *C) {
 	params, err := opts.KdfParams(32)
 	c.Assert(err, IsNil)
 	c.Check(params.Type, Equals, "pbkdf2")
+	c.Check(params.Time, Equals, expectedTime)
 	c.Check(params.Hash, Equals, HashAlg(crypto.SHA512))
 	c.Check(params.Memory, Equals, 0)
 	c.Check(params.CPUs, Equals, 0)