diff --git a/lib/security/serialization/serialization_test.go b/lib/security/serialization/serialization_test.go
index 9f7fc96..2de7519 100644
--- a/lib/security/serialization/serialization_test.go
+++ b/lib/security/serialization/serialization_test.go
@@ -83,6 +83,7 @@
 }
 
 func TestRoundTrip(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	signer := newSigner()
 	d, s := &bufferCloser{}, &bufferCloser{}
 
diff --git a/runtime/internal/lib/deque/deque_test.go b/runtime/internal/lib/deque/deque_test.go
index 0e89896..9cac8e0 100644
--- a/runtime/internal/lib/deque/deque_test.go
+++ b/runtime/internal/lib/deque/deque_test.go
@@ -136,16 +136,17 @@
 }
 
 func TestRandom(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	var q T
 	var contents []int
 	for i := 0; i != 1000; i++ {
-		switch testutil.Intn(4) {
+		switch testutil.RandomIntn(4) {
 		case 0:
-			i := testutil.Int()
+			i := testutil.RandomInt()
 			contents = append([]int{i}, contents...)
 			q.PushFront(i)
 		case 1:
-			i := testutil.Int()
+			i := testutil.RandomInt()
 			contents = append(contents, i)
 			q.PushBack(i)
 		case 2:
diff --git a/runtime/internal/lib/sync/wait_group_test.go b/runtime/internal/lib/sync/wait_group_test.go
index ff250b3..859b323 100644
--- a/runtime/internal/lib/sync/wait_group_test.go
+++ b/runtime/internal/lib/sync/wait_group_test.go
@@ -15,12 +15,13 @@
 // TestRandom tests Wait after a random sequence of TryAdd's and Done's that
 // leaves the counter at 0.
 func TestRandom(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	var w WaitGroup
 	N := 100
 
 	count := 0
 	for n := 0; n < N; n++ {
-		if count == 0 || testutil.Intn(2) == 0 {
+		if count == 0 || testutil.RandomIntn(2) == 0 {
 			if !w.TryAdd() {
 				t.Fatal("TryAdd failed")
 			}
diff --git a/runtime/internal/rpc/results_store_test.go b/runtime/internal/rpc/results_store_test.go
index b0ee8eb..b38b652 100644
--- a/runtime/internal/rpc/results_store_test.go
+++ b/runtime/internal/rpc/results_store_test.go
@@ -13,10 +13,10 @@
 )
 
 func randomKeys() []uint64 {
-	n := (testutil.Intn(256*10) / 10) + 256
+	n := (testutil.RandomIntn(256*10) / 10) + 256
 	k := make([]uint64, n)
 	for i := 0; i < n; i++ {
-		k[i] = uint64(testutil.Int63())
+		k[i] = uint64(testutil.RandomInt63())
 	}
 	return k
 }
@@ -29,6 +29,7 @@
 func (p keySlice) Sort()              { sort.Sort(p) }
 
 func TestStoreRandom(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	store := newStore()
 	keys := randomKeys()
 
@@ -50,6 +51,7 @@
 }
 
 func TestStoreOrdered(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	store := newStore()
 	keys := randomKeys()
 
@@ -94,6 +96,7 @@
 }
 
 func TestStoreWaitForEntryRandom(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	store := newStore()
 	keys := randomKeys()
 	var wg sync.WaitGroup
@@ -115,6 +118,7 @@
 }
 
 func TestStoreWaitForRemovedEntry(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	store := newStore()
 	keys := randomKeys()
 	var wg sync.WaitGroup
diff --git a/runtime/internal/rpc/stream/manager/manager_test.go b/runtime/internal/rpc/stream/manager/manager_test.go
index b2a5cad..6fe2ddd 100644
--- a/runtime/internal/rpc/stream/manager/manager_test.go
+++ b/runtime/internal/rpc/stream/manager/manager_test.go
@@ -917,6 +917,7 @@
 	}
 	var stderr bytes.Buffer
 	if err := h.Shutdown(nil, &stderr); err != nil {
+		t.Logf("%s", stderr.String())
 		t.Fatal(err)
 	}
 	if log := expect.NewSession(t, bytes.NewReader(stderr.Bytes()), time.Minute).ExpectSetEventuallyRE("listener.go.*Killing [1-9][0-9]* Conns"); len(log) == 0 {
diff --git a/runtime/internal/rpc/stream/vc/vc_test.go b/runtime/internal/rpc/stream/vc/vc_test.go
index 1c08719..e42c385 100644
--- a/runtime/internal/rpc/stream/vc/vc_test.go
+++ b/runtime/internal/rpc/stream/vc/vc_test.go
@@ -62,12 +62,13 @@
 // testFlowEcho writes a random string of 'size' bytes on the flow and then
 // ensures that the same string is read back.
 func testFlowEcho(t *testing.T, flow stream.Flow, size int) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	defer flow.Close()
 	wrote := testutil.RandomBytes(size)
 	go func() {
 		buf := wrote
 		for len(buf) > 0 {
-			limit := 1 + testutil.Intn(len(buf)) // Random number in [1, n]
+			limit := 1 + testutil.RandomIntn(len(buf)) // Random number in [1, n]
 			n, err := flow.Write(buf[:limit])
 			if n != limit || err != nil {
 				t.Errorf("Write returned (%d, %v) want (%d, nil)", n, err, limit)
diff --git a/runtime/internal/rpc/stream/vif/vif_test.go b/runtime/internal/rpc/stream/vif/vif_test.go
index 1a6aa24..101258b 100644
--- a/runtime/internal/rpc/stream/vif/vif_test.go
+++ b/runtime/internal/rpc/stream/vif/vif_test.go
@@ -85,6 +85,7 @@
 }
 
 func testMultipleVCsAndMultipleFlows(t *testing.T, gomaxprocs int) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	// This test dials multiple VCs from the client to the server.
 	// On each VC, it creates multiple flows, writes to them and verifies
 	// that the other process received what was written.
@@ -143,7 +144,7 @@
 		buf := []byte(data)
 		// Split into a random number of Write calls.
 		for len(buf) > 0 {
-			size := 1 + testutil.Intn(len(buf)) // Random number in [1, len(buf)]
+			size := 1 + testutil.RandomIntn(len(buf)) // Random number in [1, len(buf)]
 			n, err := flow.Write(buf[:size])
 			if err != nil {
 				t.Errorf("Write failed: (%d, %v)", n, err)
@@ -159,7 +160,7 @@
 		var buf bytes.Buffer
 		var tmp [1024]byte
 		for {
-			n, err := flow.Read(tmp[:testutil.Intn(len(tmp))])
+			n, err := flow.Read(tmp[:testutil.RandomIntn(len(tmp))])
 			buf.Write(tmp[:n])
 			if err == io.EOF {
 				break
diff --git a/runtime/internal/testing/concurrency/clock_test.go b/runtime/internal/testing/concurrency/clock_test.go
index 58c2cbc..dcbd6fc 100644
--- a/runtime/internal/testing/concurrency/clock_test.go
+++ b/runtime/internal/testing/concurrency/clock_test.go
@@ -14,8 +14,9 @@
 
 // TestClone checks the clone() method of a clock.
 func TestClone(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	c1 := newClock()
-	c1[0] = testutil.Intn(100)
+	c1[0] = testutil.RandomIntn(100)
 	c2 := c1.clone()
 	c1[0]++
 	if c2[0] != c1[0]-1 {
@@ -27,7 +28,7 @@
 func TestEquality(t *testing.T) {
 	c1, c2 := newClock(), newClock()
 	for i := TID(0); i < TID(10); i++ {
-		c1[i] = testutil.Intn(100)
+		c1[i] = testutil.RandomIntn(100)
 		c2[i] = c1[i]
 	}
 	if !c1.equals(c2) {
@@ -39,7 +40,7 @@
 func TestHappensBefore(t *testing.T) {
 	c1, c2, c3 := newClock(), newClock(), newClock()
 	for i := TID(0); i < TID(10); i++ {
-		c1[i] = testutil.Intn(100)
+		c1[i] = testutil.RandomIntn(100)
 		if i%2 == 0 {
 			c2[i] = c1[i] + 1
 			c3[i] = c1[i] + 1
@@ -69,8 +70,8 @@
 func TestMerge(t *testing.T) {
 	c1, c2 := newClock(), newClock()
 	for i := TID(0); i < TID(10); i++ {
-		c1[i] = testutil.Intn(100)
-		c2[i] = testutil.Intn(100)
+		c1[i] = testutil.RandomIntn(100)
+		c2[i] = testutil.RandomIntn(100)
 	}
 	c1.merge(c2)
 	for i := TID(0); i < TID(10); i++ {
diff --git a/services/binary/binaryd/binaryd_v23_test.go b/services/binary/binaryd/binaryd_v23_test.go
index e0611a6..0a3c05a 100644
--- a/services/binary/binaryd/binaryd_v23_test.go
+++ b/services/binary/binaryd/binaryd_v23_test.go
@@ -96,6 +96,7 @@
 }
 
 func V23TestBinaryRepositoryIntegration(i *v23tests.T) {
+	defer testutil.InitRandGenerator(i.Logf)()
 	v23tests.RunRootMT(i, "--v23.tcp.address=127.0.0.1:0")
 
 	// Build the required binaries.
diff --git a/services/device/internal/impl/globsuid/signature_match_test.go b/services/device/internal/impl/globsuid/signature_match_test.go
index f746394..5aabcbc 100644
--- a/services/device/internal/impl/globsuid/signature_match_test.go
+++ b/services/device/internal/impl/globsuid/signature_match_test.go
@@ -27,6 +27,7 @@
 )
 
 func TestDownloadSignatureMatch(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := utiltest.V23Init()
 	defer shutdown()
 
@@ -37,7 +38,7 @@
 	pkgVON := naming.Join(binaryVON, "testpkg")
 	defer utiltest.StartRealBinaryRepository(t, ctx, binaryVON)()
 
-	up := testutil.RandomBytes(testutil.Intn(5 << 20))
+	up := testutil.RandomBytes(testutil.RandomIntn(5 << 20))
 	mediaInfo := repository.MediaInfo{Type: "application/octet-stream"}
 	sig, err := binarylib.Upload(ctx, naming.Join(binaryVON, "testbinary"), up, mediaInfo)
 	if err != nil {
@@ -50,7 +51,7 @@
 		t.Fatalf("ioutil.TempDir failed: %v", err)
 	}
 	defer os.RemoveAll(tmpdir)
-	pkgContents := testutil.RandomBytes(testutil.Intn(5 << 20))
+	pkgContents := testutil.RandomBytes(testutil.RandomIntn(5 << 20))
 	if err := ioutil.WriteFile(filepath.Join(tmpdir, "pkg.txt"), pkgContents, 0600); err != nil {
 		t.Fatalf("ioutil.WriteFile failed: %v", err)
 	}
diff --git a/services/internal/binarylib/client_test.go b/services/internal/binarylib/client_test.go
index cd76fd6..7cd2435 100644
--- a/services/internal/binarylib/client_test.go
+++ b/services/internal/binarylib/client_test.go
@@ -83,6 +83,7 @@
 // TestBufferAPI tests the binary repository client-side library
 // interface using buffers.
 func TestBufferAPI(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := test.V23Init()
 	defer shutdown()
 
@@ -90,7 +91,7 @@
 
 	von, cleanup := setupRepository(t, ctx)
 	defer cleanup()
-	data := testutil.RandomBytes(testutil.Intn(10 << 20))
+	data := testutil.RandomBytes(testutil.RandomIntn(10 << 20))
 	mediaInfo := repository.MediaInfo{Type: "application/octet-stream"}
 	sig, err := Upload(ctx, von, data, mediaInfo)
 	if err != nil {
@@ -136,6 +137,7 @@
 // TestFileAPI tests the binary repository client-side library
 // interface using files.
 func TestFileAPI(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := test.V23Init()
 	defer shutdown()
 
@@ -144,7 +146,7 @@
 	von, cleanup := setupRepository(t, ctx)
 	defer cleanup()
 	// Create up to 10MB of random bytes.
-	data := testutil.RandomBytes(testutil.Intn(10 << 20))
+	data := testutil.RandomBytes(testutil.RandomIntn(10 << 20))
 	dir, prefix := "", ""
 	src, err := ioutil.TempFile(dir, prefix)
 	if err != nil {
diff --git a/services/internal/binarylib/http_test.go b/services/internal/binarylib/http_test.go
index 77f0f2d..5e11215 100644
--- a/services/internal/binarylib/http_test.go
+++ b/services/internal/binarylib/http_test.go
@@ -23,6 +23,7 @@
 
 // TestHTTP checks that HTTP download works.
 func TestHTTP(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := test.V23Init()
 	defer shutdown()
 
@@ -37,7 +38,7 @@
 		data := make([][]byte, length)
 		for i := 0; i < length; i++ {
 			// Random size, but at least 1 (avoid empty parts).
-			size := testutil.Intn(1000*binarylib.BufferLength) + 1
+			size := testutil.RandomIntn(1000*binarylib.BufferLength) + 1
 			data[i] = testutil.RandomBytes(size)
 		}
 		mediaInfo := repository.MediaInfo{Type: "application/octet-stream"}
diff --git a/services/internal/binarylib/impl_test.go b/services/internal/binarylib/impl_test.go
index 93bbb35..6ce83b0 100644
--- a/services/internal/binarylib/impl_test.go
+++ b/services/internal/binarylib/impl_test.go
@@ -185,6 +185,7 @@
 // resumption ranging the number of parts the uploaded binary consists
 // of.
 func TestResumption(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := test.V23Init()
 	defer shutdown()
 
@@ -216,7 +217,7 @@
 				break
 			}
 			for i := 0; i < length; i++ {
-				fail := testutil.Intn(2)
+				fail := testutil.RandomIntn(2)
 				if parts[i] == binarylib.MissingPart && fail != 0 {
 					if streamErr, err := invokeUpload(t, ctx, binary, data[i], int32(i)); streamErr != nil || err != nil {
 						t.FailNow()
@@ -232,6 +233,7 @@
 
 // TestErrors checks that the binary interface correctly reports errors.
 func TestErrors(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	ctx, shutdown := test.V23Init()
 	defer shutdown()
 
@@ -244,7 +246,7 @@
 	for i := 0; i < length; i++ {
 		data[i] = testData()
 		for j := 0; j < len(data[i]); j++ {
-			data[i][j] = byte(testutil.Int())
+			data[i][j] = byte(testutil.RandomInt())
 		}
 	}
 	if err := binary.Create(ctx, int32(length), repository.MediaInfo{Type: "application/octet-stream"}); err != nil {
diff --git a/services/internal/binarylib/util_test.go b/services/internal/binarylib/util_test.go
index 2038f46..30b414f 100644
--- a/services/internal/binarylib/util_test.go
+++ b/services/internal/binarylib/util_test.go
@@ -89,7 +89,7 @@
 
 // testData creates up to 4MB of random bytes.
 func testData() []byte {
-	size := testutil.Intn(1000 * binarylib.BufferLength)
+	size := testutil.RandomIntn(1000 * binarylib.BufferLength)
 	data := testutil.RandomBytes(size)
 	return data
 }
diff --git a/test/init.go b/test/init.go
index 395cab7..d86b452 100644
--- a/test/init.go
+++ b/test/init.go
@@ -10,11 +10,11 @@
 	"runtime"
 	"sync"
 
+	"v.io/x/lib/vlog"
+
 	"v.io/v23"
 	"v.io/v23/context"
 
-	"v.io/x/lib/vlog"
-
 	"v.io/x/ref/lib/flags"
 	"v.io/x/ref/test/testutil"
 )
@@ -58,7 +58,6 @@
 		// function of a _test.go file.
 		flag.Parse()
 		vlog.ConfigureLibraryLoggerFromFlags()
-		testutil.InitRandGenerator()
 	}
 	once.Do(init)
 }
diff --git a/test/modules/modules_test.go b/test/modules/modules_test.go
index 117b4e4..993e060 100644
--- a/test/modules/modules_test.go
+++ b/test/modules/modules_test.go
@@ -397,7 +397,6 @@
 	if got, want := stdoutBuf.String(), stdoutOutput+result; got != want {
 		t.Errorf("got %q want %q", got, want)
 	}
-	stderrBuf.ReadString('\n') // Skip past the random # generator output
 	if got, want := stderrBuf.String(), stderrOutput; got != want {
 		t.Errorf("got %q want %q", got, want)
 	}
diff --git a/test/modules/queue_rw_test.go b/test/modules/queue_rw_test.go
index 66df967..fd55475 100644
--- a/test/modules/queue_rw_test.go
+++ b/test/modules/queue_rw_test.go
@@ -14,12 +14,13 @@
 )
 
 func TestQueueRW(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	q := modules.NewRW()
-	size := testutil.Intn(1000)
+	size := testutil.RandomIntn(1000)
 	data := testutil.RandomBytes(size)
 	begin := 0
 	for {
-		end := begin + testutil.Intn(100) + 1
+		end := begin + testutil.RandomIntn(100) + 1
 		if end > len(data) {
 			end = len(data)
 		}
@@ -37,7 +38,7 @@
 	}
 	readData := make([]byte, 0, size)
 	for {
-		buf := make([]byte, testutil.Intn(100)+1)
+		buf := make([]byte, testutil.RandomIntn(100)+1)
 		n, err := q.Read(buf)
 		if n > 0 {
 			readData = append(readData, buf[:n]...)
diff --git a/test/testutil/rand.go b/test/testutil/rand.go
index e6ef82b..ca9f038 100644
--- a/test/testutil/rand.go
+++ b/test/testutil/rand.go
@@ -5,13 +5,12 @@
 package testutil
 
 import (
+	"fmt"
 	"math/rand"
 	"os"
 	"strconv"
 	"sync"
 	"time"
-
-	"v.io/x/lib/vlog"
 )
 
 const (
@@ -27,25 +26,26 @@
 // Random is a concurrent-access friendly source of randomness.
 type Random struct {
 	mu   sync.Mutex
+	seed int64
 	rand *rand.Rand
 }
 
-// Int returns a non-negative pseudo-random int.
-func (r *Random) Int() int {
+// RandomInt returns a non-negative pseudo-random int.
+func (r *Random) RandomInt() int {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	return r.rand.Int()
 }
 
-// Intn returns a non-negative pseudo-random int in the range [0, n).
-func (r *Random) Intn(n int) int {
+// RandomIntn returns a non-negative pseudo-random int in the range [0, n).
+func (r *Random) RandomIntn(n int) int {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	return r.rand.Intn(n)
 }
 
-// Int63 returns a non-negative 63-bit pseudo-random integer as an int64.
-func (r *Random) Int63() int64 {
+// RandomInt63 returns a non-negative 63-bit pseudo-random integer as an int64.
+func (r *Random) RandomInt63() int64 {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	return r.rand.Int63()
@@ -65,7 +65,7 @@
 		extra := generateRandomBytes(rand, size-len(random))
 		random = append(random, extra...)
 	}
-	start := rand.Intn(len(random) - size + 1)
+	start := rand.RandomIntn(len(random) - size + 1)
 	copy(buffer, random[start:start+size])
 	return buffer
 }
@@ -80,18 +80,25 @@
 		base, bitSize := 0, 64
 		seed, err = strconv.ParseInt(seedString, base, bitSize)
 		if err != nil {
-			vlog.Fatalf("ParseInt(%v, %v, %v) failed: %v", seedString, base, bitSize, err)
+			panic(fmt.Sprintf("ParseInt(%v, %v, %v) failed: %v", seedString, base, bitSize, err))
 		}
 	}
-	vlog.Infof("Seeding pseudo-random number generator with %v", seed)
-	return &Random{rand: rand.New(rand.NewSource(seed))}
+	return &Random{seed: seed, rand: rand.New(rand.NewSource(seed))}
 }
 
-// InitRandGenerator creates an instance of Random in the public variable Rand.
-func InitRandGenerator() {
+// InitRandGenerator creates an instance of Random in the public variable Rand
+// and returns a function intended to be defer'ed that prints out the
+// seed use when creating the number number generator using the supplied
+// logging function.
+func InitRandGenerator(loggingFunc func(format string, args ...interface{})) func() {
 	once.Do(func() {
 		Rand = NewRandGenerator()
 	})
+	return func() {
+		if loggingFunc != nil {
+			loggingFunc("Seeded pseudo-random number generator with %v", Rand.seed)
+		}
+	}
 }
 
 var (
@@ -103,7 +110,7 @@
 	buffer := make([]byte, size)
 	offset := 0
 	for {
-		bits := int64(rand.Int63())
+		bits := int64(rand.RandomInt63())
 		for i := 0; i < 8; i++ {
 			buffer[offset] = byte(bits & 0xff)
 			size--
@@ -116,21 +123,21 @@
 	}
 }
 
-// Int returns a non-negative pseudo-random int using the public variable Rand.
-func Int() int {
-	return Rand.Int()
+// RandomInt returns a non-negative pseudo-random int using the public variable Rand.
+func RandomInt() int {
+	return Rand.RandomInt()
 }
 
-// Intn returns a non-negative pseudo-random int in the range [0, n) using
+// RandomIntn returns a non-negative pseudo-random int in the range [0, n) using
 // the public variable Rand.
-func Intn(n int) int {
-	return Rand.Intn(n)
+func RandomIntn(n int) int {
+	return Rand.RandomIntn(n)
 }
 
-// Int63 returns a non-negative 63-bit pseudo-random integer as an int64
+// RandomInt63 returns a non-negative 63-bit pseudo-random integer as an int64
 // using the public variable Rand.
-func Int63() int64 {
-	return Rand.Int63()
+func RandomInt63() int64 {
+	return Rand.RandomInt63()
 }
 
 // RandomBytes generates the given number of random bytes using
diff --git a/test/testutil/security_test.go b/test/testutil/security_test.go
index f6d5a35..b13eb6b 100644
--- a/test/testutil/security_test.go
+++ b/test/testutil/security_test.go
@@ -2,16 +2,18 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package testutil
+package testutil_test
 
 import (
 	"reflect"
 	"testing"
+
+	"v.io/x/ref/test/testutil"
 )
 
 func TestIDProvider(t *testing.T) {
-	idp := NewIDProvider("foo")
-	p := NewPrincipal()
+	idp := testutil.NewIDProvider("foo")
+	p := testutil.NewPrincipal()
 	if err := idp.Bless(p, "bar"); err != nil {
 		t.Fatal(err)
 	}
diff --git a/test/testutil/testdata/rand_test.go b/test/testutil/testdata/rand_test.go
new file mode 100644
index 0000000..bddb946
--- /dev/null
+++ b/test/testutil/testdata/rand_test.go
@@ -0,0 +1,17 @@
+// Copyright 2015 The Vanadium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testutil_test
+
+import (
+	"testing"
+
+	"v.io/x/ref/test/testutil"
+)
+
+func TestRandSeed(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
+	t.Logf("rand: %d", testutil.RandomInt())
+	t.FailNow()
+}
diff --git a/test/testutil/util_test.go b/test/testutil/util_test.go
index 0a44dab..91b9aff 100644
--- a/test/testutil/util_test.go
+++ b/test/testutil/util_test.go
@@ -2,16 +2,45 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package testutil
+package testutil_test
 
 import (
 	"regexp"
 	"testing"
+
+	_ "v.io/x/ref/runtime/factories/generic"
+	"v.io/x/ref/test/testutil"
+	"v.io/x/ref/test/v23tests"
 )
 
 func TestFormatLogline(t *testing.T) {
-	line, want := FormatLogLine(2, "test"), "testing.go:.*"
+	line, want := testutil.FormatLogLine(2, "test"), "testing.go:.*"
 	if ok, err := regexp.MatchString(want, line); !ok || err != nil {
 		t.Errorf("got %v, want %v", line, want)
 	}
 }
+
+//go:generate v23 test generate .
+
+func V23TestRandSeed(i *v23tests.T) {
+	v23bin := i.BinaryFromPath("v23")
+	inv := v23bin.Start("go", "test", "./testdata")
+	inv.ExpectRE("FAIL: TestRandSeed.*", 1)
+	parts := inv.ExpectRE(`rand: (\d+)`, -1)
+	if len(parts) != 1 || len(parts[0]) != 2 {
+		i.Fatalf("failed to match regexp")
+	}
+	randInt := parts[0][1]
+	parts = inv.ExpectRE(`Seeded pseudo-random number generator with (\d+)`, -1)
+	if len(parts) != 1 || len(parts[0]) != 2 {
+		i.Fatalf("failed to match regexp")
+	}
+
+	seed := parts[0][1]
+	// Rerun the test, this time with the seed that we want to use.
+	v23bin = v23bin.WithEnv("V23_RNG_SEED=" + seed)
+	inv = v23bin.Start("go", "test", "./testdata")
+	inv.ExpectRE("FAIL: TestRandSeed.*", 1)
+	inv.ExpectRE("rand: "+randInt, 1)
+	inv.ExpectRE("Seeded pseudo-random number generator with "+seed, -1)
+}
diff --git a/test/testutil/v23_test.go b/test/testutil/v23_test.go
new file mode 100644
index 0000000..0463ee0
--- /dev/null
+++ b/test/testutil/v23_test.go
@@ -0,0 +1,30 @@
+// Copyright 2015 The Vanadium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file was auto-generated via go generate.
+// DO NOT UPDATE MANUALLY
+
+package testutil_test
+
+import (
+	"os"
+	"testing"
+
+	"v.io/x/ref/test"
+	"v.io/x/ref/test/modules"
+	"v.io/x/ref/test/v23tests"
+)
+
+func TestMain(m *testing.M) {
+	test.Init()
+	modules.DispatchAndExitIfChild()
+	cleanup := v23tests.UseSharedBinDir()
+	r := m.Run()
+	cleanup()
+	os.Exit(r)
+}
+
+func TestV23RandSeed(t *testing.T) {
+	v23tests.RunTest(t, V23TestRandSeed)
+}
diff --git a/test/testutil/vtest_test.go b/test/testutil/vtest_test.go
index 0bd33cc..516fe06 100644
--- a/test/testutil/vtest_test.go
+++ b/test/testutil/vtest_test.go
@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package testutil
+package testutil_test
 
 import (
 	"testing"
+
+	"v.io/x/ref/test/testutil"
 )
 
 func TestCallAndRecover(t *testing.T) {
@@ -19,7 +21,7 @@
 		{func() { panic("abc") }, "abc"},
 	}
 	for _, test := range tests {
-		got := CallAndRecover(test.f)
+		got := testutil.CallAndRecover(test.f)
 		if got != test.expect {
 			t.Errorf(`CallAndRecover got "%v", want "%v"`, got, test.expect)
 		}
diff --git a/test/v23tests/v23tests_test.go b/test/v23tests/v23tests_test.go
index 63efeb9..47c8d4c 100644
--- a/test/v23tests/v23tests_test.go
+++ b/test/v23tests/v23tests_test.go
@@ -143,6 +143,7 @@
 }
 
 func TestInputRedirection(t *testing.T) {
+	defer testutil.InitRandGenerator(t.Logf)()
 	env := v23tests.New(t)
 	defer env.Cleanup()
 
@@ -296,7 +297,7 @@
 		msg := recover().(string)
 		// this, and the tests below are intended to ensure that line #s
 		// are captured and reported correctly.
-		if got, want := msg, "v23tests_test.go:306"; !strings.Contains(got, want) {
+		if got, want := msg, "v23tests_test.go:307"; !strings.Contains(got, want) {
 			t.Fatalf("%q does not contain %q", got, want)
 		}
 		if got, want := msg, "fork/exec /bin/echox: no such file or directory"; !strings.Contains(got, want) {
@@ -318,7 +319,7 @@
 	sh.SetDefaultStartOpts(opts)
 	defer func() {
 		msg := recover().(string)
-		if got, want := msg, "v23tests_test.go:328"; !strings.Contains(got, want) {
+		if got, want := msg, "v23tests_test.go:329"; !strings.Contains(got, want) {
 			t.Fatalf("%q does not contain %q", got, want)
 		}
 		if got, want := msg, "StartWithOpts"; !strings.Contains(got, want) {
@@ -342,7 +343,7 @@
 		if iterations == 0 {
 			t.Fatalf("our sleeper didn't get to run")
 		}
-		if got, want := recover().(string), "v23tests_test.go:349: timed out"; !strings.Contains(got, want) {
+		if got, want := recover().(string), "v23tests_test.go:350: timed out"; !strings.Contains(got, want) {
 			t.Fatalf("%q does not contain %q", got, want)
 		}
 	}()
@@ -364,7 +365,7 @@
 		if iterations != 0 {
 			t.Fatalf("our sleeper got to run")
 		}
-		if got, want := recover().(string), "v23tests_test.go:371: timed out"; !strings.Contains(got, want) {
+		if got, want := recover().(string), "v23tests_test.go:372: timed out"; !strings.Contains(got, want) {
 			t.Fatalf("%q does not contain %q", got, want)
 		}
 	}()