diff --git a/data/test_trackers/tracker_moodbot.json b/data/test_trackers/tracker_moodbot.json
index 32dddd3f097b..190ec328dc65 100644
--- a/data/test_trackers/tracker_moodbot.json
+++ b/data/test_trackers/tracker_moodbot.json
@@ -39,6 +39,7 @@
     "rasa_corrected_slots": null,
     "rasa_previous_flow": null,
     "requested_slot": null,
+    "return_value": null,
     "session_started_metadata": null
   },
   "latest_input_channel": null,
diff --git a/rasa/shared/core/constants.py b/rasa/shared/core/constants.py
index 06a5cdb83b02..aa4d14c262d6 100644
--- a/rasa/shared/core/constants.py
+++ b/rasa/shared/core/constants.py
@@ -89,12 +89,14 @@
 PREVIOUS_FLOW_SLOT = "rasa_previous_flow"
 CANCELLED_FLOW_SLOT = "rasa_cancelled_flow"
 CORRECTED_SLOTS_SLOT = "rasa_corrected_slots"
+RETURN_VALUE_SLOT = "return_value"
 
 FLOW_SLOT_NAMES = [
     FLOW_STACK_SLOT,
     PREVIOUS_FLOW_SLOT,
     CANCELLED_FLOW_SLOT,
     CORRECTED_SLOTS_SLOT,
+    RETURN_VALUE_SLOT,
 ]
 
 # slots for knowledge base
diff --git a/tests/core/test_actions.py b/tests/core/test_actions.py
index de22be687c02..3c14df2ac38a 100644
--- a/tests/core/test_actions.py
+++ b/tests/core/test_actions.py
@@ -97,6 +97,7 @@
     CANCELLED_FLOW_SLOT,
     PREVIOUS_FLOW_SLOT,
     CORRECTED_SLOTS_SLOT,
+    RETURN_VALUE_SLOT,
 )
 from rasa.shared.core.trackers import DialogueStateTracker
 from rasa.shared.exceptions import RasaException
@@ -249,6 +250,7 @@ async def test_remote_action_runs(
                     CANCELLED_FLOW_SLOT: None,
                     CORRECTED_SLOTS_SLOT: None,
                     PREVIOUS_FLOW_SLOT: None,
+                    RETURN_VALUE_SLOT: None,
                 },
                 "events": [],
                 "latest_input_channel": None,
@@ -315,6 +317,7 @@ async def test_remote_action_logs_events(
                     CANCELLED_FLOW_SLOT: None,
                     CORRECTED_SLOTS_SLOT: None,
                     PREVIOUS_FLOW_SLOT: None,
+                    RETURN_VALUE_SLOT: None,
                 },
                 "events": [],
                 "latest_input_channel": None,
diff --git a/tests/shared/core/test_domain.py b/tests/shared/core/test_domain.py
index 19393b61df05..6d2695835388 100644
--- a/tests/shared/core/test_domain.py
+++ b/tests/shared/core/test_domain.py
@@ -924,6 +924,7 @@ def test_domain_from_multiple_files():
         "rasa_corrected_slots",
         "rasa_previous_flow",
         "requested_slot",
+        "return_value",
         "session_started_metadata",
     ]
 
diff --git a/tests/shared/importers/test_rasa.py b/tests/shared/importers/test_rasa.py
index 7c873cd3acc5..a141fc541965 100644
--- a/tests/shared/importers/test_rasa.py
+++ b/tests/shared/importers/test_rasa.py
@@ -16,6 +16,7 @@
     PREVIOUS_FLOW_SLOT,
     CANCELLED_FLOW_SLOT,
     CORRECTED_SLOTS_SLOT,
+    RETURN_VALUE_SLOT,
 )
 from rasa.shared.core.domain import Domain
 from rasa.shared.core.slots import AnySlot
@@ -37,6 +38,7 @@ def test_rasa_file_importer(project: Text):
         AnySlot(PREVIOUS_FLOW_SLOT, mappings=[{}]),
         AnySlot(CANCELLED_FLOW_SLOT, mappings=[{}]),
         AnySlot(CORRECTED_SLOTS_SLOT, mappings=[{}]),
+        AnySlot(RETURN_VALUE_SLOT, mappings=[{}]),
         AnySlot(SESSION_START_METADATA_SLOT, mappings=[{}]),
     ]
     assert domain.entities == []
diff --git a/tests/test_server.py b/tests/test_server.py
index 46c3e8ed4ddb..fd9fe2361221 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -59,6 +59,7 @@
     CANCELLED_FLOW_SLOT,
     CORRECTED_SLOTS_SLOT,
     PREVIOUS_FLOW_SLOT,
+    RETURN_VALUE_SLOT,
 )
 from rasa.shared.core.domain import Domain, SessionConfig
 from rasa.shared.core.events import (
@@ -1124,6 +1125,7 @@ async def test_requesting_non_existent_tracker(rasa_app: SanicASGITestClient):
         CANCELLED_FLOW_SLOT: None,
         CORRECTED_SLOTS_SLOT: None,
         PREVIOUS_FLOW_SLOT: None,
+        RETURN_VALUE_SLOT: None,
     }
     assert content["sender_id"] == "madeupid"
     assert content["events"] == [