diff --git a/CHANGES/3995.bugfix b/CHANGES/3995.bugfix
new file mode 100644
index 0000000000..acfdd5ad32
--- /dev/null
+++ b/CHANGES/3995.bugfix
@@ -0,0 +1 @@
+Fix api schema of the `upstream_pulp_replicate` operation requiring no body.
diff --git a/pulpcore/app/viewsets/replica.py b/pulpcore/app/viewsets/replica.py
index 5d9d8aa8b7..666f671b38 100644
--- a/pulpcore/app/viewsets/replica.py
+++ b/pulpcore/app/viewsets/replica.py
@@ -33,6 +33,7 @@ class UpstreamPulpViewSet(
         summary="Replicate",
         description="Trigger an asynchronous repository replication task group. This API is "
         "provided as a tech preview.",
+        request=None,
         responses={202: AsyncOperationResponseSerializer},
     )
     @action(detail=True, methods=["post"])