diff --git a/gns3server/api/routes/controller/links.py b/gns3server/api/routes/controller/links.py
index 1bddff2d1..522f692cc 100644
--- a/gns3server/api/routes/controller/links.py
+++ b/gns3server/api/routes/controller/links.py
@@ -497,7 +497,7 @@ async def delete_marker(
 )
 async def update_marker(
     marker_name: str,
-    marker_data: schemas.MarkerCreate,
+    marker_data: schemas.MarkerUpdate,
     link: Link = Depends(dep_link)
 ) -> dict:
     """
diff --git a/gns3server/schemas/__init__.py b/gns3server/schemas/__init__.py
index 7c8b9cab2..fc18b73af 100644
--- a/gns3server/schemas/__init__.py
+++ b/gns3server/schemas/__init__.py
@@ -20,7 +20,7 @@ from .common import ErrorMessage
 from .version import Version
 
 # Controller schemas
-from .controller.links import LinkCreate, LinkUpdate, Link, UDPPortInfo, EthernetPortInfo, LinkCapture, MarkerCreate, MarkerDefinitionCreate
+from .controller.links import LinkCreate, LinkUpdate, Link, UDPPortInfo, EthernetPortInfo, LinkCapture, MarkerCreate, MarkerUpdate, MarkerDefinitionCreate
 from .controller.computes import ComputeCreate, ComputeUpdate, ComputeVirtualBoxVM, ComputeVMwareVM, ComputeDockerImage, AutoIdlePC, Compute
 from .controller.templates import TemplateCreate, TemplateUpdate, TemplateUsage, Template
 from .controller.images import Image, ImageType
diff --git a/gns3server/schemas/controller/links.py b/gns3server/schemas/controller/links.py
index 3ec06c5d5..31bdc607a 100644
--- a/gns3server/schemas/controller/links.py
+++ b/gns3server/schemas/controller/links.py
@@ -191,6 +191,29 @@ class MarkerCreate(BaseModel):
     )
 
 
+class MarkerUpdate(BaseModel):
+    """
+    Body for updating a marker — partial update, every field optional.
+
+    ``bpf`` is optional here (it is required on create). ``capture_node_id`` and
+    ``name`` are create-only / path-driven and intentionally absent; an explicit
+    ``direction: null`` clears the direction back to both (omitting keeps it).
+    """
+
+    bpf: Optional[str] = None
+    tag: Optional[int] = None
+    direction: Optional[str] = Field(
+        None,
+        pattern=r"^(tx|rx)$",
+        description="Direction filter; an explicit null clears it to both. Omit to keep.",
+    )
+    color: Optional[str] = Field(None, description="Hex color render hint, e.g. '#ff5722'")
+    highlight_duration: Optional[int] = Field(
+        None, ge=1, description="UI highlight duration in ms; null = UI default"
+    )
+    enabled: Optional[bool] = Field(None, description="Toggle the marker on/off (instant).")
+
+
 class MarkerDefinitionCreate(BaseModel):
     """
     Body for creating / updating a project-level marker definition.