diff --git a/assignment-client/src/AssignmentAction.cpp b/assignment-client/src/AssignmentAction.cpp
index 107a80cf14..388f4123f6 100644
--- a/assignment-client/src/AssignmentAction.cpp
+++ b/assignment-client/src/AssignmentAction.cpp
@@ -24,16 +24,24 @@ AssignmentAction::~AssignmentAction() {
 }
 
 void AssignmentAction::removeFromSimulation(EntitySimulation* simulation) const {
-    simulation->removeAction(_id);
-    simulation->applyActionChanges();
+    withReadLock([&]{
+        simulation->removeAction(_id);
+        simulation->applyActionChanges();
+    });
 }
 
 QByteArray AssignmentAction::serialize() const {
-    return _data;
+    QByteArray result;
+    withReadLock([&]{
+        result = _data;
+    });
+    return result;
 }
 
 void AssignmentAction::deserialize(QByteArray serializedArguments) {
-    _data = serializedArguments;
+    withWriteLock([&]{
+        _data = serializedArguments;
+    });
 }
 
 bool AssignmentAction::updateArguments(QVariantMap arguments) {
diff --git a/assignment-client/src/AssignmentAction.h b/assignment-client/src/AssignmentAction.h
index 23720bd465..6b901c9766 100644
--- a/assignment-client/src/AssignmentAction.h
+++ b/assignment-client/src/AssignmentAction.h
@@ -19,7 +19,7 @@
 #include "EntityActionInterface.h"
 
 
-class AssignmentAction : public EntityActionInterface {
+class AssignmentAction : public EntityActionInterface, public ReadWriteLockable {
 public:
     AssignmentAction(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~AssignmentAction();