diff --git a/src/savegame.cpp b/src/savegame.cpp
index b063bc4496d4d..507cadf1a24b8 100644
--- a/src/savegame.cpp
+++ b/src/savegame.cpp
@@ -1585,7 +1585,19 @@ void faction_manager::serialize( JsonOut &jsout ) const
 
 void faction_manager::deserialize( JsonIn &jsin )
 {
-    jsin.read( factions );
+    jsin.start_array();
+    while( !jsin.end_array() ) {
+        faction add_fac;
+        jsin.read( add_fac );
+        faction *old_fac = get( add_fac.id );
+        if( old_fac ) {
+            *old_fac = add_fac;
+            // force a revalidation of add_fac
+            get( add_fac.id );
+        } else {
+            factions.emplace_back( add_fac );
+        }
+    }
 }
 
 void Creature_tracker::deserialize( JsonIn &jsin )
diff --git a/src/savegame_json.cpp b/src/savegame_json.cpp
index a3981409556d4..1d4445a0d0a8c 100644
--- a/src/savegame_json.cpp
+++ b/src/savegame_json.cpp
@@ -1527,7 +1527,7 @@ void npc::store( JsonOut &json ) const
     json.member( "previous_mission", previous_mission );
     json.member( "faction_api_ver", faction_api_version );
     if( !fac_id.str().empty() ) { // set in constructor
-        json.member( "my_fac", my_fac->id.c_str() );
+        json.member( "my_fac", fac_id.c_str() );
     }
     json.member( "attitude", static_cast<int>( attitude ) );
     json.member( "previous_attitude", static_cast<int>( attitude ) );