diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..6bd296c
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,11 @@
+module github.com/whyrusleeping/pubsub
+
+go 1.17
+
+require github.com/stretchr/testify v1.7.1
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..2dca7c9
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,11 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/pubsub.go b/pubsub.go
index 9cbf9cf..5b432e9 100644
--- a/pubsub.go
+++ b/pubsub.go
@@ -74,13 +74,24 @@ func (ps *PubSub) Pub(msg interface{}, topics ...string) {
 
 // Unsub unsubscribes the given channel from the specified
 // topics. If no topic is specified, it is unsubscribed
-// from all topics.
+// from all topics and the channel is drained.
+//
+// If topics _are_ specified, it is up to the caller to keep draining the subscription channel.
 func (ps *PubSub) Unsub(ch chan interface{}, topics ...string) {
 	if len(topics) == 0 {
-		ps.cmdChan <- cmd{op: unsubAll, ch: ch}
-		return
+		// Keep trying to unsubscribe while also draining the channel to prevent any
+		// deadlocks.
+		for {
+			select {
+			case ps.cmdChan <- cmd{op: unsubAll, ch: ch}:
+				// Drain the sub channel.
+				for range ch {
+				}
+				return
+			case <-ch:
+			}
+		}
 	}
-
 	ps.cmdChan <- cmd{op: unsub, topics: topics, ch: ch}
 }
 
diff --git a/pubsub_test.go b/pubsub_test.go
index 64c1901..250dd44 100644
--- a/pubsub_test.go
+++ b/pubsub_test.go
@@ -4,109 +4,107 @@
 
 package pubsub
 
-/*
 import (
-	check "launchpad.net/gocheck"
 	"runtime"
 	"testing"
 	"time"
-)
-
-var _ = check.Suite(new(Suite))
-
-func Test(t *testing.T) {
-	check.TestingT(t)
-}
 
-type Suite struct{}
+	"github.com/stretchr/testify/require"
+)
 
-func (s *Suite) TestSub(c *check.C) {
+func TestSub(t *testing.T) {
 	ps := New(1)
 	ch1 := ps.Sub("t1")
 	ch2 := ps.Sub("t1")
 	ch3 := ps.Sub("t2")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch1, check.Equals, "hi")
-	c.Check(<-ch2, check.Equals, "hi")
+	require.Equal(t, <-ch1, "hi")
+	require.Equal(t, <-ch2, "hi")
 
 	ps.Pub("hello", "t2")
-	c.Check(<-ch3, check.Equals, "hello")
+	require.Equal(t, <-ch3, "hello")
 
 	ps.Shutdown()
 	_, ok := <-ch1
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	_, ok = <-ch2
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	_, ok = <-ch3
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 }
 
-func (s *Suite) TestSubOnce(c *check.C) {
+func TestSubOnce(t *testing.T) {
 	ps := New(1)
 	ch := ps.SubOnce("t1")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch, check.Equals, "hi")
+	require.Equal(t, <-ch, "hi")
 
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	ps.Shutdown()
 }
 
-func (s *Suite) TestAddSub(c *check.C) {
+func TestAddSub(t *testing.T) {
 	ps := New(1)
 	ch1 := ps.Sub("t1")
 	ch2 := ps.Sub("t2")
 
 	ps.Pub("hi1", "t1")
-	c.Check(<-ch1, check.Equals, "hi1")
+	require.Equal(t, <-ch1, "hi1")
 
 	ps.Pub("hi2", "t2")
-	c.Check(<-ch2, check.Equals, "hi2")
+	require.Equal(t, <-ch2, "hi2")
 
 	ps.AddSub(ch1, "t2", "t3")
 	ps.Pub("hi3", "t2")
-	c.Check(<-ch1, check.Equals, "hi3")
-	c.Check(<-ch2, check.Equals, "hi3")
+	require.Equal(t, <-ch1, "hi3")
+	require.Equal(t, <-ch2, "hi3")
 
 	ps.Pub("hi4", "t3")
-	c.Check(<-ch1, check.Equals, "hi4")
+	require.Equal(t, <-ch1, "hi4")
 
 	ps.Shutdown()
 }
 
-func (s *Suite) TestUnsub(c *check.C) {
+func TestUnsub(t *testing.T) {
 	ps := New(1)
 	ch := ps.Sub("t1")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch, check.Equals, "hi")
+	require.Equal(t, <-ch, "hi")
 
 	ps.Unsub(ch, "t1")
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	ps.Shutdown()
 }
 
-func (s *Suite) TestUnsubAll(c *check.C) {
+func TestUnsubAll(t *testing.T) {
 	ps := New(1)
 	ch1 := ps.Sub("t1", "t2", "t3")
 	ch2 := ps.Sub("t1", "t3")
 
 	ps.Unsub(ch1)
 
-	m, ok := <-ch1
-	c.Check(ok, check.Equals, false)
+	_, ok := <-ch1
+	require.Equal(t, ok, false)
 
 	ps.Pub("hi", "t1")
-	m, ok = <-ch2
-	c.Check(m, check.Equals, "hi")
+	m := <-ch2
+	require.Equal(t, m, "hi")
+
+	ps.Pub("bye", "t1")
+	ps.Unsub(ch2)
+	_, ok = <-ch2
+	// unsubscribing all should drain channel.
+	require.Equal(t, ok, false)
 
 	ps.Shutdown()
 }
 
-func (s *Suite) TestClose(c *check.C) {
+func TestClose(t *testing.T) {
 	ps := New(1)
 	ch1 := ps.Sub("t1")
 	ch2 := ps.Sub("t1")
@@ -115,25 +113,25 @@ func (s *Suite) TestClose(c *check.C) {
 
 	ps.Pub("hi", "t1")
 	ps.Pub("hello", "t2")
-	c.Check(<-ch1, check.Equals, "hi")
-	c.Check(<-ch2, check.Equals, "hi")
-	c.Check(<-ch3, check.Equals, "hello")
+	require.Equal(t, <-ch1, "hi")
+	require.Equal(t, <-ch2, "hi")
+	require.Equal(t, <-ch3, "hello")
 
 	ps.Close("t1", "t2")
 	_, ok := <-ch1
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	_, ok = <-ch2
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	_, ok = <-ch3
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 
 	ps.Pub("welcome", "t3")
-	c.Check(<-ch4, check.Equals, "welcome")
+	require.Equal(t, <-ch4, "welcome")
 
 	ps.Shutdown()
 }
 
-func (s *Suite) TestUnsubAfterClose(c *check.C) {
+func TestUnsubAfterClose(t *testing.T) {
 	ps := New(1)
 	ch := ps.Sub("t1")
 	defer func() {
@@ -143,58 +141,61 @@ func (s *Suite) TestUnsubAfterClose(c *check.C) {
 
 	ps.Close("t1")
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 }
 
-func (s *Suite) TestShutdown(c *check.C) {
+func TestShutdown(t *testing.T) {
 	start := runtime.NumGoroutine()
-	New(10).Shutdown()
-	time.Sleep(1)
-	c.Check(runtime.NumGoroutine()-start, check.Equals, 1)
+	for i := 0; i < 10; i++ {
+		New(10).Shutdown()
+	}
+	time.Sleep(1 * time.Second)
+	// 2 because go...
+	require.LessOrEqual(t, runtime.NumGoroutine()-start, 2)
 }
 
-func (s *Suite) TestMultiSub(c *check.C) {
+func TestMultiSub(t *testing.T) {
 	ps := New(1)
 	ch := ps.Sub("t1", "t2")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch, check.Equals, "hi")
+	require.Equal(t, <-ch, "hi")
 
 	ps.Pub("hello", "t2")
-	c.Check(<-ch, check.Equals, "hello")
+	require.Equal(t, <-ch, "hello")
 
 	ps.Shutdown()
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 }
 
-func (s *Suite) TestMultiSubOnce(c *check.C) {
+func TestMultiSubOnce(t *testing.T) {
 	ps := New(1)
 	ch := ps.SubOnce("t1", "t2")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch, check.Equals, "hi")
+	require.Equal(t, <-ch, "hi")
 
 	ps.Pub("hello", "t2")
 
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 	ps.Shutdown()
 }
 
-func (s *Suite) TestMultiPub(c *check.C) {
+func TestMultiPub(t *testing.T) {
 	ps := New(1)
 	ch1 := ps.Sub("t1")
 	ch2 := ps.Sub("t2")
 
 	ps.Pub("hi", "t1", "t2")
-	c.Check(<-ch1, check.Equals, "hi")
-	c.Check(<-ch2, check.Equals, "hi")
+	require.Equal(t, <-ch1, "hi")
+	require.Equal(t, <-ch2, "hi")
 
 	ps.Shutdown()
 }
 
-func (s *Suite) TestMultiUnsub(c *check.C) {
+func TestMultiUnsub(t *testing.T) {
 	ps := New(1)
 	ch := ps.Sub("t1", "t2", "t3")
 
@@ -203,30 +204,29 @@ func (s *Suite) TestMultiUnsub(c *check.C) {
 	ps.Pub("hi", "t1")
 
 	ps.Pub("hello", "t2")
-	c.Check(<-ch, check.Equals, "hello")
+	require.Equal(t, <-ch, "hello")
 
 	ps.Unsub(ch, "t2", "t3")
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 
 	ps.Shutdown()
 }
 
-func (s *Suite) TestMultiClose(c *check.C) {
+func TestMultiClose(t *testing.T) {
 	ps := New(1)
 	ch := ps.Sub("t1", "t2")
 
 	ps.Pub("hi", "t1")
-	c.Check(<-ch, check.Equals, "hi")
+	require.Equal(t, <-ch, "hi")
 
 	ps.Close("t1")
 	ps.Pub("hello", "t2")
-	c.Check(<-ch, check.Equals, "hello")
+	require.Equal(t, <-ch, "hello")
 
 	ps.Close("t2")
 	_, ok := <-ch
-	c.Check(ok, check.Equals, false)
+	require.Equal(t, ok, false)
 
 	ps.Shutdown()
 }
-*/