diff --git a/server/src/lib/score-mutation/update-score.test.ts b/server/src/lib/score-mutation/update-score.test.ts
index ba8d96d67..9bd67add8 100644
--- a/server/src/lib/score-mutation/update-score.test.ts
+++ b/server/src/lib/score-mutation/update-score.test.ts
@@ -6,6 +6,7 @@ import db from "external/mongo/db";
 import UpdateScore from "./update-score";
 import { CreateScoreID } from "lib/score-import/framework/score-importing/score-id";
 import ResetDBState from "test-utils/resets";
+import { rootLogger } from "lib/logger/logger";
 
 const mockImportDocument: ImportDocument = {
 	userID: 1,
@@ -61,8 +62,12 @@ t.test("#UpdateScore", (t) => {
 			scoreData: { score: 1020 },
 		} as any);
 
+		delete score._id;
+
 		const newScoreID = CreateScoreID(score.userID, score, score.chartID);
 
+		rootLogger.crit(newScoreID);
+
 		await db.imports.insert(mockImportDocument);
 		await db.sessions.insert(mockSessionDocument);
 
diff --git a/server/src/lib/score-mutation/update-score.ts b/server/src/lib/score-mutation/update-score.ts
index f2f0f4f0c..ba956e5b5 100644
--- a/server/src/lib/score-mutation/update-score.ts
+++ b/server/src/lib/score-mutation/update-score.ts
@@ -4,6 +4,7 @@ import { KtLogger, rootLogger } from "lib/logger/logger";
 import { CreateCalculatedData } from "lib/score-import/framework/calculated-data/calculated-data";
 import { UpdateChartRanking } from "lib/score-import/framework/pb/create-pb-doc";
 import { CreateScoreID } from "lib/score-import/framework/score-importing/score-id";
+import { id } from "monk";
 import { ScoreDocument } from "tachi-common";
 import { UpdateAllPBs } from "utils/calculations/recalc-scores";
 import { FormatUserDoc, GetUserWithID } from "utils/user";
@@ -67,6 +68,15 @@ export default async function UpdateScore(oldScore: ScoreDocument, newScore: Sco
 	);
 
 	try {
+		// Having _id defined will cause this to throw, causing it to not apply
+		// the update.
+		if (newScore._id) {
+			logger.warn(
+				`Passed a score with _id to UpdateScore. This property should not be set. Deleting this property and continuing anyway.`
+			);
+			// This property shouldn't be defined.
+			delete newScore._id;
+		}
 		await db.scores.update(
 			{
 				scoreID: oldScoreID,