diff --git a/gateway/app/routers/edits.py b/gateway/app/routers/edits.py
index a1dcd0e..45265a3 100644
--- a/gateway/app/routers/edits.py
+++ b/gateway/app/routers/edits.py
@@ -190,6 +190,24 @@ class DeleteAnnotationOperation(BaseModel):
     data: DeleteAnnotationData
 
 
+class UpdateAnnotationData(BaseModel):
+    annotationId: str
+    x: float | None = None
+    y: float | None = None
+    width: float | None = None
+    height: float | None = None
+    color: str | None = None
+    thickness: float | None = None
+    text: str | None = None
+
+
+class UpdateAnnotationOperation(BaseModel):
+    id: str
+    type: Literal["update_annotation"]
+    pageIndex: int = Field(..., ge=0)
+    data: UpdateAnnotationData
+
+
 EditOperation = Annotated[
     TextOverlayOperation
     | RedactionOperation
@@ -202,7 +220,8 @@ EditOperation = Annotated[
     | PageDeletionOperation
     | PageReorderOperation
     | UpdateFieldOperation
-    | DeleteAnnotationOperation,
+    | DeleteAnnotationOperation
+    | UpdateAnnotationOperation,
     Field(discriminator="type"),
 ]