diff --git a/test/hold_effect_berserk_gene.c b/test/hold_effect_berserk_gene.c
index 361d148611..103a0a1a3e 100644
--- a/test/hold_effect_berserk_gene.c
+++ b/test/hold_effect_berserk_gene.c
@@ -11,14 +11,11 @@ SINGLE_BATTLE_TEST("Berserk Gene sharply raises attack at the start of battle",
     u16 useItem;
     PARAMETRIZE { useItem = FALSE; }
     PARAMETRIZE { useItem = TRUE; }
-    if (useItem) PASSES_RANDOMLY(66, 100, RNG_CONFUSION);
     GIVEN {
-        PLAYER(SPECIES_WOBBUFFET) { if (useItem) Item(ITEM_BERSERK_GENE); };
+        PLAYER(SPECIES_WOBBUFFET) { if (useItem) Item(ITEM_BERSERK_GENE); }
         OPPONENT(SPECIES_WOBBUFFET);
     } WHEN {
-        TURN {
-            MOVE(player, MOVE_TACKLE);
-        }
+        TURN { MOVE(player, MOVE_TACKLE, WITH_RNG(RNG_CONFUSION, FALSE)); }
     } SCENE {
         if (useItem)
         {
@@ -38,17 +35,13 @@ SINGLE_BATTLE_TEST("Berserk Gene activates on switch in", s16 damage)
     u16 useItem;
     PARAMETRIZE { useItem = FALSE; }
     PARAMETRIZE { useItem = TRUE; }
-    if (useItem) PASSES_RANDOMLY(66, 100, RNG_CONFUSION);
     GIVEN {
         PLAYER(SPECIES_WYNAUT);
-        PLAYER(SPECIES_WOBBUFFET) { if (useItem) Item(ITEM_BERSERK_GENE); };
+        PLAYER(SPECIES_WOBBUFFET) { if (useItem) Item(ITEM_BERSERK_GENE); }
         OPPONENT(SPECIES_WOBBUFFET);
     } WHEN {
-        TURN {
-            SWITCH(player, 1);
-        } TURN {
-            MOVE(player, MOVE_TACKLE);
-        }
+        TURN { SWITCH(player, 1); }
+        TURN { MOVE(player, MOVE_TACKLE, WITH_RNG(RNG_CONFUSION, FALSE)); }
     } SCENE {
         if (useItem)
         {
diff --git a/test/test_runner_battle.c b/test/test_runner_battle.c
index b7360e19c8..c1ea34e8cb 100644
--- a/test/test_runner_battle.c
+++ b/test/test_runner_battle.c
@@ -939,6 +939,8 @@ static bool32 BattleTest_HandleExitWithResult(void *data, enum TestResult result
 
 void Randomly(u32 sourceLine, u32 passes, u32 trials, struct RandomlyContext ctx)
 {
+    const struct BattleTest *test = gTestRunnerState.test->data;
+    INVALID_IF(test->resultsSize > 0, "PASSES_RANDOMLY is incompatible with results");
     INVALID_IF(passes > trials, "%d passes specified, but only %d trials", passes, trials);
     STATE->rngTag = ctx.tag;
     STATE->runTrial = 0;