diff --git a/task_test.go b/task_test.go
index 33c3a3099b..14a1b3d63e 100644
--- a/task_test.go
+++ b/task_test.go
@@ -37,6 +37,18 @@ type SyncBuffer struct {
 	mu  sync.Mutex
 }
 
+func (sb *SyncBuffer) String() string {
+	sb.mu.Lock()
+	defer sb.mu.Unlock()
+	return sb.buf.String()
+}
+
+func (sb *SyncBuffer) Reset() {
+	sb.mu.Lock()
+	defer sb.mu.Unlock()
+	sb.buf.Reset()
+}
+
 func (sb *SyncBuffer) Write(p []byte) (n int, err error) {
 	sb.mu.Lock()
 	defer sb.mu.Unlock()
@@ -179,7 +191,7 @@ func TestSpecialVars(t *testing.T) {
 	for _, dir := range []string{dir, subdir} {
 		for _, test := range tests {
 			t.Run(test.target, func(t *testing.T) {
-				var buff bytes.Buffer
+				var buff SyncBuffer
 				e := &task.Executor{
 					Dir:    dir,
 					Stdout: &buff,
@@ -188,7 +200,7 @@ func TestSpecialVars(t *testing.T) {
 				}
 				require.NoError(t, e.Setup())
 				require.NoError(t, e.Run(context.Background(), &ast.Call{Task: test.target}))
-				assert.Equal(t, test.expected+"\n", buff.String())
+				assert.Equal(t, test.expected+"\n", buff.buf.String())
 			})
 		}
 	}
@@ -286,7 +298,7 @@ func TestStatus(t *testing.T) {
 		}
 	}
 
-	var buff bytes.Buffer
+	var buff SyncBuffer
 	e := &task.Executor{
 		Dir: dir,
 		TempDir: task.TempDir{
@@ -322,7 +334,7 @@ func TestStatus(t *testing.T) {
 	require.NoError(t, e.Run(context.Background(), &ast.Call{Task: "gen-bar"}))
 
 	// We're silent, so no output should have been produced.
-	assert.Empty(t, buff.String())
+	assert.Empty(t, buff.buf.String())
 
 	// Now, let's remove source file, and run the task again to to prepare
 	// for the next test.
@@ -371,7 +383,7 @@ func TestStatus(t *testing.T) {
 func TestPrecondition(t *testing.T) {
 	const dir = "testdata/precondition"
 
-	var buff bytes.Buffer
+	var buff SyncBuffer
 	e := &task.Executor{
 		Dir:    dir,
 		Stdout: &buff,
@@ -486,7 +498,7 @@ func TestStatusChecksum(t *testing.T) {
 				require.Error(t, err)
 			}
 
-			var buff bytes.Buffer
+			var buff SyncBuffer
 			tempdir := task.TempDir{
 				Remote:      filepathext.SmartJoin(dir, ".task"),
 				Fingerprint: filepathext.SmartJoin(dir, ".task"),
@@ -1735,7 +1747,7 @@ func TestRunOnlyRunsJobsHashOnce(t *testing.T) {
 func TestRunOnceSharedDeps(t *testing.T) {
 	const dir = "testdata/run_once_shared_deps"
 
-	var buff bytes.Buffer
+	var buff SyncBuffer
 	e := task.Executor{
 		Dir:      dir,
 		Stdout:   &buff,
@@ -1746,10 +1758,10 @@ func TestRunOnceSharedDeps(t *testing.T) {
 	require.NoError(t, e.Run(context.Background(), &ast.Call{Task: "build"}))
 
 	rx := regexp.MustCompile(`task: \[service-[a,b]:library:build\] echo "build library"`)
-	matches := rx.FindAllStringSubmatch(buff.String(), -1)
+	matches := rx.FindAllStringSubmatch(buff.buf.String(), -1)
 	assert.Len(t, matches, 1)
-	assert.Contains(t, buff.String(), `task: [service-a:build] echo "build a"`)
-	assert.Contains(t, buff.String(), `task: [service-b:build] echo "build b"`)
+	assert.Contains(t, buff.buf.String(), `task: [service-a:build] echo "build a"`)
+	assert.Contains(t, buff.buf.String(), `task: [service-b:build] echo "build b"`)
 }
 
 func TestDeferredCmds(t *testing.T) {
@@ -2412,8 +2424,8 @@ func TestForCmds(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			var stdOut bytes.Buffer
-			var stdErr bytes.Buffer
+			var stdOut SyncBuffer
+			var stdErr SyncBuffer
 			e := task.Executor{
 				Dir:    "testdata/for/cmds",
 				Stdout: &stdOut,
@@ -2423,7 +2435,7 @@ func TestForCmds(t *testing.T) {
 			}
 			require.NoError(t, e.Setup())
 			require.NoError(t, e.Run(context.Background(), &ast.Call{Task: test.name}))
-			assert.Equal(t, test.expectedOutput, stdOut.String())
+			assert.Equal(t, test.expectedOutput, stdOut.buf.String())
 		})
 	}
 }
diff --git a/taskfile/ast/task.go b/taskfile/ast/task.go
index de6986c6b8..39543188b5 100644
--- a/taskfile/ast/task.go
+++ b/taskfile/ast/task.go
@@ -43,7 +43,7 @@ type Task struct {
 	Watch         bool
 	Location      *Location
 	// Populated during merging
-	Namespace            string
+	Namespace            []string
 	IncludeVars          *Vars
 	IncludedTaskfileVars *Vars
 }
@@ -57,8 +57,10 @@ func (t *Task) Name() string {
 
 func (t *Task) LocalName() string {
 	name := t.Task
-	name = strings.TrimPrefix(name, t.Namespace)
-	name = strings.TrimPrefix(name, ":")
+	for _, namespace := range t.Namespace {
+		name = strings.TrimPrefix(name, namespace)
+		name = strings.TrimPrefix(name, ":")
+	}
 	return name
 }
 
@@ -219,7 +221,7 @@ func (t *Task) DeepCopy() *Task {
 		Platforms:            deepcopy.Slice(t.Platforms),
 		Location:             t.Location.DeepCopy(),
 		Requires:             t.Requires.DeepCopy(),
-		Namespace:            t.Namespace,
+		Namespace:            append([]string{}, t.Namespace...),
 	}
 	return c
 }
diff --git a/taskfile/ast/tasks.go b/taskfile/ast/tasks.go
index cfe29a8da3..6cf356c55a 100644
--- a/taskfile/ast/tasks.go
+++ b/taskfile/ast/tasks.go
@@ -87,7 +87,7 @@ func (t1 *Tasks) Merge(t2 Tasks, include *Include, includedTaskfileVars *Vars) e
 			}
 
 			taskName = taskNameWithNamespace(name, include.Namespace)
-			task.Namespace = include.Namespace
+			task.Namespace = append([]string{include.Namespace}, task.Namespace...)
 			task.Task = taskName
 		}