diff --git a/internal/commands/extension_test.go b/internal/commands/extension_test.go
new file mode 100644
index 000000000..396d77290
--- /dev/null
+++ b/internal/commands/extension_test.go
@@ -0,0 +1,51 @@
+package commands_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/sclevine/spec"
+	"github.com/sclevine/spec/report"
+	"github.com/spf13/cobra"
+
+	"github.com/buildpacks/pack/internal/commands"
+	"github.com/buildpacks/pack/internal/commands/fakes"
+	"github.com/buildpacks/pack/internal/commands/testmocks"
+	"github.com/buildpacks/pack/internal/config"
+	"github.com/buildpacks/pack/pkg/logging"
+	h "github.com/buildpacks/pack/testhelpers"
+)
+
+func TestExtensionCommand(t *testing.T) {
+	spec.Run(t, "ExtensionCommand", testExtensionCommand, spec.Parallel(), spec.Report(report.Terminal{}))
+}
+
+func testExtensionCommand(t *testing.T, when spec.G, it spec.S) {
+	var (
+		cmd        *cobra.Command
+		logger     logging.Logger
+		outBuf     bytes.Buffer
+		mockClient *testmocks.MockPackClient
+	)
+
+	it.Before(func() {
+		logger = logging.NewLogWithWriters(&outBuf, &outBuf)
+		mockController := gomock.NewController(t)
+		mockClient = testmocks.NewMockPackClient(mockController)
+		cmd = commands.NewExtensionCommand(logger, config.Config{}, mockClient, fakes.NewFakePackageConfigReader())
+		cmd.SetOut(logging.GetWriterForLevel(logger, logging.InfoLevel))
+	})
+
+	when("extension", func() {
+		it("prints help text", func() {
+			cmd.SetArgs([]string{})
+			h.AssertNil(t, cmd.Execute())
+			output := outBuf.String()
+			h.AssertContains(t, output, "Interact with extensions")
+			for _, command := range []string{"Usage", "package", "register", "yank", "pull", "inspect"} {
+				h.AssertContains(t, output, command)
+			}
+		})
+	})
+}
diff --git a/pkg/testmocks/mock_build_module.go b/pkg/testmocks/mock_build_module.go
index 80ae2f965..5548ad6f6 100644
--- a/pkg/testmocks/mock_build_module.go
+++ b/pkg/testmocks/mock_build_module.go
@@ -10,7 +10,7 @@ import (
 
 	gomock "github.com/golang/mock/gomock"
 
-	buildmodule "github.com/buildpacks/pack/pkg/buildpack"
+	buildpack "github.com/buildpacks/pack/pkg/buildpack"
 )
 
 // MockBuildModule is a mock of BuildModule interface.
@@ -37,10 +37,10 @@ func (m *MockBuildModule) EXPECT() *MockBuildModuleMockRecorder {
 }
 
 // Descriptor mocks base method.
-func (m *MockBuildModule) Descriptor() buildmodule.Descriptor {
+func (m *MockBuildModule) Descriptor() buildpack.Descriptor {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Descriptor")
-	ret0, _ := ret[0].(buildmodule.Descriptor)
+	ret0, _ := ret[0].(buildpack.Descriptor)
 	return ret0
 }
 
diff --git a/pkg/testmocks/mock_buildpack_downloader.go b/pkg/testmocks/mock_buildpack_downloader.go
index 724ce467c..d67ff548d 100644
--- a/pkg/testmocks/mock_buildpack_downloader.go
+++ b/pkg/testmocks/mock_buildpack_downloader.go
@@ -10,7 +10,7 @@ import (
 
 	gomock "github.com/golang/mock/gomock"
 
-	buildmodule "github.com/buildpacks/pack/pkg/buildpack"
+	buildpack "github.com/buildpacks/pack/pkg/buildpack"
 )
 
 // MockBuildpackDownloader is a mock of BuildpackDownloader interface.
@@ -37,11 +37,11 @@ func (m *MockBuildpackDownloader) EXPECT() *MockBuildpackDownloaderMockRecorder
 }
 
 // Download mocks base method.
-func (m *MockBuildpackDownloader) Download(arg0 context.Context, arg1 string, arg2 buildmodule.DownloadOptions) (buildmodule.BuildModule, []buildmodule.BuildModule, error) {
+func (m *MockBuildpackDownloader) Download(arg0 context.Context, arg1 string, arg2 buildpack.DownloadOptions) (buildpack.BuildModule, []buildpack.BuildModule, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Download", arg0, arg1, arg2)
-	ret0, _ := ret[0].(buildmodule.BuildModule)
-	ret1, _ := ret[1].([]buildmodule.BuildModule)
+	ret0, _ := ret[0].(buildpack.BuildModule)
+	ret1, _ := ret[1].([]buildpack.BuildModule)
 	ret2, _ := ret[2].(error)
 	return ret0, ret1, ret2
 }