diff --git a/lib/galaxy/model/__init__.py b/lib/galaxy/model/__init__.py
index cfb70740308e..f4821d1985c6 100644
--- a/lib/galaxy/model/__init__.py
+++ b/lib/galaxy/model/__init__.py
@@ -2630,7 +2630,9 @@ class PostJobAction(Base, RepresentById):
     workflow_step_id: Mapped[Optional[int]] = mapped_column(ForeignKey("workflow_step.id"), index=True)
     action_type: Mapped[str] = mapped_column(String(255))
     output_name: Mapped[Optional[str]] = mapped_column(String(255))
-    _action_arguments: Mapped[Optional[bytes]] = mapped_column(MutableJSONType)
+    _action_arguments: Mapped[Optional[Union[bool, Dict[str, Any]]]] = mapped_column(
+        "action_arguments", MutableJSONType
+    )
     workflow_step: Mapped[Optional["WorkflowStep"]] = relationship(
         back_populates="post_job_actions",
         primaryjoin=(lambda: WorkflowStep.id == PostJobAction.workflow_step_id),