diff --git a/osu.Game/Scoring/ScoreModelManager.cs b/osu.Game/Scoring/ScoreModelManager.cs
index fcf7244226..5ba152fad3 100644
--- a/osu.Game/Scoring/ScoreModelManager.cs
+++ b/osu.Game/Scoring/ScoreModelManager.cs
@@ -63,6 +63,11 @@ namespace osu.Game.Scoring
             if (!model.Ruleset.IsManaged)
                 model.Ruleset = realm.Find<RulesetInfo>(model.Ruleset.ShortName);
 
+            // These properties are known to be non-null, but these final checks ensure a null hasn't come from somewhere (or the refetch has failed).
+            // Under no circumstance do we want these to be written to realm as null.
+            if (model.BeatmapInfo == null) throw new ArgumentNullException(nameof(model.BeatmapInfo));
+            if (model.Ruleset == null) throw new ArgumentNullException(nameof(model.Ruleset));
+
             if (string.IsNullOrEmpty(model.StatisticsJson))
                 model.StatisticsJson = JsonConvert.SerializeObject(model.Statistics);
         }
diff --git a/osu.Game/Stores/BeatmapImporter.cs b/osu.Game/Stores/BeatmapImporter.cs
index 3ebdcde296..5303bd6fba 100644
--- a/osu.Game/Stores/BeatmapImporter.cs
+++ b/osu.Game/Stores/BeatmapImporter.cs
@@ -64,7 +64,7 @@ namespace osu.Game.Stores
                 // ensure we aren't trying to add a new ruleset to the database
                 // this can happen in tests, mostly
                 if (!b.Ruleset.IsManaged)
-                    b.Ruleset = realm.Find<RulesetInfo>(b.Ruleset.ShortName);
+                    b.Ruleset = realm.Find<RulesetInfo>(b.Ruleset.ShortName) ?? throw new ArgumentNullException(nameof(b.Ruleset));
             }
 
             validateOnlineIds(beatmapSet, realm);