diff --git a/Code/Framework/AzFramework/Tests/Mocks/MockSpawnableEntitiesInterface.h b/Code/Framework/AzFramework/Tests/Mocks/MockSpawnableEntitiesInterface.h
index a437545adf..4d04fa5bc9 100644
--- a/Code/Framework/AzFramework/Tests/Mocks/MockSpawnableEntitiesInterface.h
+++ b/Code/Framework/AzFramework/Tests/Mocks/MockSpawnableEntitiesInterface.h
@@ -36,7 +36,7 @@ namespace AzFramework
 
         MOCK_METHOD3(
             SpawnEntities,
-            void(EntitySpawnTicket& ticket, AZStd::vector<size_t> entityIndices, SpawnEntitiesOptionalArgs optionalArgs));
+            void(EntitySpawnTicket& ticket, AZStd::vector<uint32_t> entityIndices, SpawnEntitiesOptionalArgs optionalArgs));
 
         MOCK_METHOD2(DespawnAllEntities, void(EntitySpawnTicket& ticket, DespawnAllEntitiesOptionalArgs optionalArgs));
 
@@ -49,6 +49,13 @@ namespace AzFramework
             ReloadSpawnable,
             void(EntitySpawnTicket& ticket, AZ::Data::Asset<Spawnable> spawnable, ReloadSpawnableOptionalArgs optionalArgs));
 
+        MOCK_METHOD3(
+            UpdateEntityAliasTypes,
+            void(
+                EntitySpawnTicket& ticket,
+                AZStd::vector<EntityAliasTypeChange> updatedAliases,
+                UpdateEntityAliasTypesOptionalArgs optionalArgs));
+
         MOCK_METHOD3(
             ListEntities, void(EntitySpawnTicket& ticket, ListEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs));
 
@@ -61,6 +68,7 @@ namespace AzFramework
             void(EntitySpawnTicket& ticket, ClaimEntitiesCallback listCallback, ClaimEntitiesOptionalArgs optionalArgs));
 
         MOCK_METHOD3(Barrier, void(EntitySpawnTicket& ticket, BarrierCallback completionCallback, BarrierOptionalArgs optionalArgs));
+        MOCK_METHOD3(LoadBarrier, void(EntitySpawnTicket& ticket, BarrierCallback completionCallback, LoadBarrierOptionalArgs optionalArgs));
 
         MOCK_METHOD1(CreateTicket, AZStd::pair<EntitySpawnTicket::Id, void*>(AZ::Data::Asset<Spawnable>&& spawnable));
         MOCK_METHOD1(DestroyTicket, void(void* ticket));
diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
index ab3c52f6d0..5e552aad3f 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
@@ -8,6 +8,7 @@
 
 #include <AzToolsFramework/Prefab/Spawnable/SpawnableUtils.h>
 
+#include <AzCore/Casting/numeric_cast.h>
 #include <AzCore/Component/ComponentApplicationBus.h>
 #include <AzCore/Component/Entity.h>
 #include <AzCore/Component/EntityUtils.h>
@@ -297,7 +298,7 @@ namespace AzToolsFramework::Prefab::SpawnableUtils
         {
             if ((*it)->GetId() == entity)
             {
-                return AZStd::distance(begin, it);
+                return aznumeric_caster(AZStd::distance(begin, it));
             }
         }
         return InvalidEntityIndex;