diff --git a/app/objects/score.py b/app/objects/score.py
index 1051e18d..c9c72601 100644
--- a/app/objects/score.py
+++ b/app/objects/score.py
@@ -324,8 +324,6 @@ def calculate_performance(self, beatmap_id: int) -> tuple[float, float]:
             mode=mode_vn,
             mods=int(self.mods),
             combo=self.max_combo,
-            # prefer to use the score's specific params that add up to the acc
-            acc=self.acc,
             ngeki=self.ngeki,
             n300=self.n300,
             nkatu=self.nkatu,
diff --git a/app/usecases/performance.py b/app/usecases/performance.py
index 5db4f029..2c2ed101 100644
--- a/app/usecases/performance.py
+++ b/app/usecases/performance.py
@@ -18,6 +18,7 @@ class ScoreParams:
     combo: int | None = None
 
     # caller may pass either acc OR 300/100/50/geki/katu/miss
+    # passing both will result in a value error being raised
     acc: float | None = None
 
     n300: int | None = None
@@ -60,21 +61,26 @@ def calculate_performances(
     osu_file_path: str,
     scores: Iterable[ScoreParams],
 ) -> list[PerformanceResult]:
+    """\
+    Calculate performance for multiple scores on a single beatmap.
+
+    Typically most useful for mass-recalculation situations.
+
+    TODO: Some level of error handling & returning to caller should be
+    implemented here to handle cases where e.g. the beatmap file is invalid
+    or there an issue during calculation.
+    """
     calc_bmap = Beatmap(path=osu_file_path)
 
     results: list[PerformanceResult] = []
 
     for score in scores:
-        # assert either acc OR 300/100/50/geki/katu/miss is present, but not both
-        # if (score.acc is None) == (
-        #     score.n300 is None
-        #     and score.n100 is None
-        #     and score.n50 is None
-        #     and score.ngeki is None
-        #     and score.nkatu is None
-        #     and score.nmiss is None
-        # ):
-        #     raise ValueError("Either acc OR 300/100/50/geki/katu/miss must be present")
+        if score.acc and (
+            score.n300 or score.n100 or score.n50 or score.ngeki or score.nkatu
+        ):
+            raise ValueError(
+                "Must not specify accuracy AND 300/100/50/geki/katu. Only one or the other.",
+            )
 
         # rosupp ignores NC and requires DT
         if score.mods is not None:
diff --git a/tests/integration/domains/osu_test.py b/tests/integration/domains/osu_test.py
index 49adc7ef..30c6f086 100644
--- a/tests/integration/domains/osu_test.py
+++ b/tests/integration/domains/osu_test.py
@@ -239,5 +239,5 @@ async def test_score_submission(
     assert response.status_code == status.HTTP_200_OK
     assert (
         response.read()
-        == b"beatmapId:315|beatmapSetId:141|beatmapPlaycount:1|beatmapPasscount:1|approvedDate:2014-05-18 15:41:48|\n|chartId:beatmap|chartUrl:https://osu.cmyui.xyz/s/141|chartName:Beatmap Ranking|rankBefore:|rankAfter:1|rankedScoreBefore:|rankedScoreAfter:26810|totalScoreBefore:|totalScoreAfter:26810|maxComboBefore:|maxComboAfter:52|accuracyBefore:|accuracyAfter:81.94|ppBefore:|ppAfter:10.041|onlineScoreId:1|\n|chartId:overall|chartUrl:https://cmyui.xyz/u/3|chartName:Overall Ranking|rankBefore:|rankAfter:1|rankedScoreBefore:|rankedScoreAfter:26810|totalScoreBefore:|totalScoreAfter:26810|maxComboBefore:|maxComboAfter:52|accuracyBefore:|accuracyAfter:81.94|ppBefore:|ppAfter:10|achievements-new:osu-skill-pass-4+Insanity Approaches+You're not twitching, you're just ready./all-intro-hidden+Blindsight+I can see just perfectly"
+        == b"beatmapId:315|beatmapSetId:141|beatmapPlaycount:1|beatmapPasscount:1|approvedDate:2014-05-18 15:41:48|\n|chartId:beatmap|chartUrl:https://osu.cmyui.xyz/s/141|chartName:Beatmap Ranking|rankBefore:|rankAfter:1|rankedScoreBefore:|rankedScoreAfter:26810|totalScoreBefore:|totalScoreAfter:26810|maxComboBefore:|maxComboAfter:52|accuracyBefore:|accuracyAfter:81.94|ppBefore:|ppAfter:10.313|onlineScoreId:1|\n|chartId:overall|chartUrl:https://cmyui.xyz/u/3|chartName:Overall Ranking|rankBefore:|rankAfter:1|rankedScoreBefore:|rankedScoreAfter:26810|totalScoreBefore:|totalScoreAfter:26810|maxComboBefore:|maxComboAfter:52|accuracyBefore:|accuracyAfter:81.94|ppBefore:|ppAfter:11|achievements-new:osu-skill-pass-4+Insanity Approaches+You're not twitching, you're just ready./all-intro-hidden+Blindsight+I can see just perfectly"
     )
diff --git a/tools/recalc.py b/tools/recalc.py
index 172a5053..d7c019d3 100644
--- a/tools/recalc.py
+++ b/tools/recalc.py
@@ -66,7 +66,6 @@ async def recalculate_score(
     calculator = Calculator(
         mode=GameMode(score["mode"]).as_vanilla,
         mods=score["mods"],
-        acc=score["acc"],
         combo=score["max_combo"],
         n_geki=score["ngeki"],  # Mania 320s
         n300=score["n300"],