diff --git a/weed/command/filer_sync.go b/weed/command/filer_sync.go
index 29fbd2262..397bb4193 100644
--- a/weed/command/filer_sync.go
+++ b/weed/command/filer_sync.go
@@ -694,10 +694,10 @@ func destKey(dataSink sink.ReplicationSink, targetPath, sourcePath string, sourc
 		relative = strings.TrimPrefix(sk, "/")
 	}
 	if !dataSink.IsIncremental() {
-		return escapeKey(util.Join(targetPath, relative))
+		return util.Join(targetPath, relative)
 	}
 	dateKey := time.Unix(mTime, 0).Format("2006-01-02")
-	return escapeKey(util.Join(targetPath, dateKey, relative))
+	return util.Join(targetPath, dateKey, relative)
 }
 
 // isEntryExcluded checks whether a single side (old or new) of an event is excluded
diff --git a/weed/command/filer_sync_process_test.go b/weed/command/filer_sync_process_test.go
index 5febfb3d6..726319c6b 100644
--- a/weed/command/filer_sync_process_test.go
+++ b/weed/command/filer_sync_process_test.go
@@ -1,6 +1,7 @@
 package command
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
@@ -12,9 +13,10 @@ import (
 var _ sink.ReplicationSink = (*recordingSyncSink)(nil)
 
 type recordingSyncSink struct {
-	deleteKeys []string
-	createKeys []string
-	updateKeys []string
+	deleteKeys  []string
+	createKeys  []string
+	updateKeys  []string
+	incremental bool
 }
 
 func (s *recordingSyncSink) GetName() string { return "recording" }
@@ -35,7 +37,27 @@ func (s *recordingSyncSink) UpdateEntry(key string, oldEntry *filer_pb.Entry, ne
 }
 func (s *recordingSyncSink) GetSinkToDirectory() string         { return "/dest" }
 func (s *recordingSyncSink) SetSourceFiler(*source.FilerSource) {}
-func (s *recordingSyncSink) IsIncremental() bool                { return false }
+func (s *recordingSyncSink) IsIncremental() bool                { return s.incremental }
+
+// TestDestKeyPreservesColonForNonLocalSink guards against the command layer
+// stripping colons from keys destined for non-local sinks. Colon
+// sanitization belongs to the local filesystem sink only.
+func TestDestKeyPreservesColonForNonLocalSink(t *testing.T) {
+	t.Run("non-incremental", func(t *testing.T) {
+		got := destKey(&recordingSyncSink{}, "/backup", "/src", util.FullPath("/src/2024:01:02/file:name.txt"), 0)
+		want := "/backup/2024:01:02/file:name.txt"
+		if got != want {
+			t.Errorf("destKey() = %q, want %q", got, want)
+		}
+	})
+	t.Run("incremental", func(t *testing.T) {
+		got := destKey(&recordingSyncSink{incremental: true}, "/backup", "/src", util.FullPath("/src/file:name.txt"), 0)
+		// the date partition varies by timezone; assert the colon-bearing name survives.
+		if !strings.HasPrefix(got, "/backup/") || !strings.HasSuffix(got, "/file:name.txt") {
+			t.Errorf("destKey() = %q, want /backup/<date>/file:name.txt with colon preserved", got)
+		}
+	})
+}
 
 func TestPathIsEqualOrUnderUsesDirectoryBoundaries(t *testing.T) {
 	tests := []struct {
diff --git a/weed/command/filer_sync_std.go b/weed/command/filer_sync_std.go
deleted file mode 100644
index 801333751..000000000
--- a/weed/command/filer_sync_std.go
+++ /dev/null
@@ -1,7 +0,0 @@
-//go:build !windows
-
-package command
-
-func escapeKey(key string) string {
-	return key
-}
diff --git a/weed/command/filer_sync_windows.go b/weed/command/filer_sync_windows.go
deleted file mode 100644
index 3d0c9146e..000000000
--- a/weed/command/filer_sync_windows.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package command
-
-import (
-	"strings"
-)
-
-func escapeKey(key string) string {
-	if strings.Contains(key, ":") {
-		return strings.ReplaceAll(key, ":", "")
-	}
-	return key
-}
diff --git a/weed/replication/sink/localsink/local_sink.go b/weed/replication/sink/localsink/local_sink.go
index 47e1f6dae..8d1724170 100644
--- a/weed/replication/sink/localsink/local_sink.go
+++ b/weed/replication/sink/localsink/local_sink.go
@@ -61,6 +61,7 @@ func (localsink *LocalSink) IsIncremental() bool {
 }
 
 func (localsink *LocalSink) DeleteEntry(key string, isDirectory, deleteIncludeChunks bool, signatures []int32) error {
+	key = sanitizeFsKey(key)
 	if localsink.isMultiPartEntry(key) {
 		return nil
 	}
@@ -72,6 +73,7 @@ func (localsink *LocalSink) DeleteEntry(key string, isDirectory, deleteIncludeCh
 }
 
 func (localsink *LocalSink) CreateEntry(key string, entry *filer_pb.Entry, signatures []int32) error {
+	key = sanitizeFsKey(key)
 	if entry.IsDirectory || localsink.isMultiPartEntry(key) {
 		return nil
 	}
@@ -151,6 +153,7 @@ func (localsink *LocalSink) CreateEntry(key string, entry *filer_pb.Entry, signa
 }
 
 func (localsink *LocalSink) UpdateEntry(key string, oldEntry *filer_pb.Entry, newParentPath string, newEntry *filer_pb.Entry, deleteIncludeChunks bool, signatures []int32) (foundExistingEntry bool, err error) {
+	key = sanitizeFsKey(key)
 	if localsink.isMultiPartEntry(key) {
 		return true, nil
 	}
diff --git a/weed/replication/sink/localsink/local_sink_std.go b/weed/replication/sink/localsink/local_sink_std.go
new file mode 100644
index 000000000..9b7a0f28c
--- /dev/null
+++ b/weed/replication/sink/localsink/local_sink_std.go
@@ -0,0 +1,9 @@
+//go:build !windows
+
+package localsink
+
+// sanitizeFsKey is a no-op on non-Windows filesystems. The Windows build
+// strips characters that are illegal in NTFS paths.
+func sanitizeFsKey(key string) string {
+	return key
+}
diff --git a/weed/replication/sink/localsink/local_sink_std_test.go b/weed/replication/sink/localsink/local_sink_std_test.go
new file mode 100644
index 000000000..fd202fa5c
--- /dev/null
+++ b/weed/replication/sink/localsink/local_sink_std_test.go
@@ -0,0 +1,12 @@
+//go:build !windows
+
+package localsink
+
+import "testing"
+
+func TestSanitizeFsKeyKeepsColons(t *testing.T) {
+	key := "/backup/a:b/c:d.txt"
+	if got := sanitizeFsKey(key); got != key {
+		t.Errorf("sanitizeFsKey(%q) = %q, want identity", key, got)
+	}
+}
diff --git a/weed/replication/sink/localsink/local_sink_windows.go b/weed/replication/sink/localsink/local_sink_windows.go
new file mode 100644
index 000000000..631351ba8
--- /dev/null
+++ b/weed/replication/sink/localsink/local_sink_windows.go
@@ -0,0 +1,21 @@
+//go:build windows
+
+package localsink
+
+import "strings"
+
+// sanitizeFsKey strips characters illegal in NTFS paths (notably ':') so the
+// local filesystem sink can write the key. A leading drive-letter colon (e.g.
+// "C:\...") is preserved so absolute target paths stay valid. Only the local
+// sink needs this; other sinks accept the raw key.
+func sanitizeFsKey(key string) string {
+	prefix, rest := "", key
+	if len(key) >= 2 && key[1] == ':' && isDriveLetter(key[0]) {
+		prefix, rest = key[:2], key[2:]
+	}
+	return prefix + strings.ReplaceAll(rest, ":", "")
+}
+
+func isDriveLetter(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z')
+}
diff --git a/weed/replication/sink/localsink/local_sink_windows_test.go b/weed/replication/sink/localsink/local_sink_windows_test.go
new file mode 100644
index 000000000..97a9658a5
--- /dev/null
+++ b/weed/replication/sink/localsink/local_sink_windows_test.go
@@ -0,0 +1,65 @@
+//go:build windows
+
+package localsink
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/replication/source"
+)
+
+func TestSanitizeFsKeyStripsColons(t *testing.T) {
+	if got := sanitizeFsKey("/backup/a:b/c:d.txt"); got != "/backup/ab/cd.txt" {
+		t.Errorf("sanitizeFsKey() = %q, want %q", got, "/backup/ab/cd.txt")
+	}
+	if got := sanitizeFsKey(`C:\a:b`); got != `C:\ab` {
+		t.Errorf("sanitizeFsKey() = %q, want drive letter preserved %q", got, `C:\ab`)
+	}
+}
+
+// TestCreateEntryWritesSanitizedPath confirms CreateEntry strips colons from
+// the destination path before writing, so keys land at NTFS-legal paths.
+func TestCreateEntryWritesSanitizedPath(t *testing.T) {
+	tmpDir := t.TempDir()
+	sink := &LocalSink{}
+	sink.initialize(tmpDir, false)
+	sink.SetSourceFiler(&source.FilerSource{})
+
+	key := filepath.Join(tmpDir, "20:24", "fi:le.txt")
+	entry := &filer_pb.Entry{
+		Attributes: &filer_pb.FuseAttributes{FileMode: uint32(0644)},
+		Content:    []byte("data"),
+	}
+	if err := sink.CreateEntry(key, entry, nil); err != nil {
+		t.Fatalf("CreateEntry failed: %v", err)
+	}
+
+	want := sanitizeFsKey(key)
+	if _, err := os.Stat(want); err != nil {
+		t.Errorf("expected file at sanitized path %q: %v", want, err)
+	}
+	if _, err := os.Stat(key); err == nil {
+		t.Errorf("unexpected file at unsanitized path %q", key)
+	}
+
+	updated := &filer_pb.Entry{
+		Attributes: &filer_pb.FuseAttributes{FileMode: uint32(0644)},
+		Content:    []byte("data-v2"),
+	}
+	if _, err := sink.UpdateEntry(key, entry, filepath.Dir(key), updated, false, nil); err != nil {
+		t.Fatalf("UpdateEntry failed: %v", err)
+	}
+	if _, err := os.Stat(want); err != nil {
+		t.Errorf("expected updated file at sanitized path %q: %v", want, err)
+	}
+
+	if err := sink.DeleteEntry(key, false, false, nil); err != nil {
+		t.Fatalf("DeleteEntry failed: %v", err)
+	}
+	if _, err := os.Stat(want); !os.IsNotExist(err) {
+		t.Errorf("expected sanitized path %q removed, stat err=%v", want, err)
+	}
+}