diff --git a/asm/macros/battle_script.inc b/asm/macros/battle_script.inc
index c4bfea9a5f..b524104a36 100644
--- a/asm/macros/battle_script.inc
+++ b/asm/macros/battle_script.inc
@@ -2465,6 +2465,12 @@
 	1:
 	.endm
 
+	.macro jumpifabilitycantbesuppressed battler:req, jumpInstr:req
+	callnative BS_JumpIfAbilityCantBeSuppressed
+	.byte \battler
+	.4byte \jumpInstr
+	.endm
+
 	.macro setallytonexttarget jumpInstr:req
 	jumpifbyte CMP_GREATER_THAN, gBattlerTarget, 0x1, 1f
 	addbyte gBattlerTarget, 0x2
diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index e7e494008a..a10dfaa40c 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -9520,9 +9520,12 @@ BattleScript_NeutralizingGasExits::
 	setbyte gBattlerAttacker, 0
 BattleScript_NeutralizingGasExitsLoop:
 	copyarraywithindex gBattlerTarget, gBattlerByTurnOrder, gBattlerAttacker, 1
+	jumpifabilitycantbesuppressed BS_TARGET, BattleScript_NeutralizingGasExitsLoopIncrement
+	jumpifability BS_TARGET, ABILITY_IMPOSTER, BattleScript_NeutralizingGasExitsLoopIncrement @ Imposter only activates when first entering the field
 	saveattacker
 	switchinabilities BS_TARGET
 	restoreattacker
+BattleScript_NeutralizingGasExitsLoopIncrement:
 	addbyte gBattlerAttacker, 1
 	jumpifbytenotequal gBattlerAttacker, gBattlersCount, BattleScript_NeutralizingGasExitsLoop
 	restoreattacker
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index 4e6109e93b..bd2ef1509e 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -7653,7 +7653,7 @@ static void Cmd_switchindataupdate(void)
         u32 side = GetBattlerSide(battler);
         u32 partyIndex = gBattlerPartyIndexes[battler];
         if (TestRunner_Battle_GetForcedAbility(side, partyIndex))
-            gBattleMons[battler].ability = gDisableStructs[battler].overwrittenAbility = TestRunner_Battle_GetForcedAbility(side, partyIndex);
+            gBattleMons[battler].ability = TestRunner_Battle_GetForcedAbility(side, partyIndex);
     }
     #endif
 
@@ -16542,6 +16542,9 @@ static void Cmd_tryworryseed(void)
     }
     else
     {
+        if (gBattleMons[gBattlerTarget].ability == ABILITY_NEUTRALIZING_GAS)
+            gSpecialStatuses[gBattlerTarget].neutralizingGasRemoved = TRUE;
+
         gBattleScripting.abilityPopupOverwrite = gBattleMons[gBattlerTarget].ability;
         gBattleMons[gBattlerTarget].ability = gDisableStructs[gBattlerTarget].overwrittenAbility = ABILITY_INSOMNIA;
         gBattlescriptCurrInstr = cmd->nextInstr;
@@ -18742,3 +18745,14 @@ void BS_JumpIfNoWhiteOut(void)
     else
         gBattlescriptCurrInstr = cmd->nextInstr;
 }
+
+void BS_JumpIfAbilityCantBeSuppressed(void)
+{
+    NATIVE_ARGS(u8 battler, const u8 *jumpInstr);
+    u32 battler = GetBattlerForBattleScript(cmd->battler);
+
+    if (gAbilitiesInfo[gBattleMons[battler].ability].cantBeSuppressed)
+        gBattlescriptCurrInstr = cmd->jumpInstr;
+    else
+        gBattlescriptCurrInstr = cmd->nextInstr;
+}
diff --git a/src/battle_util.c b/src/battle_util.c
index 715f8bb3da..ebb11c4c7f 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -3505,7 +3505,11 @@ u32 AbilityBattleEffects(u32 caseID, u32 battler, u32 ability, u32 special, u32
                 u32 diagonalBattler = BATTLE_OPPOSITE(battler);
                 if (IsDoubleBattle())
                     diagonalBattler = BATTLE_PARTNER(diagonalBattler);
-                if (IsBattlerAlive(diagonalBattler)
+
+                // Imposter only activates when the battler first switches in
+                if (gDisableStructs[battler].isFirstTurn == 2
+                    && !gDisableStructs[battler].overwrittenAbility
+                    && IsBattlerAlive(diagonalBattler)
                     && !(gBattleMons[diagonalBattler].status2 & (STATUS2_TRANSFORMED | STATUS2_SUBSTITUTE))
                     && !(gBattleMons[battler].status2 & STATUS2_TRANSFORMED)
                     && gBattleStruct->illusion[diagonalBattler].state != ILLUSION_ON
diff --git a/test/battle/ability/neutralizing_gas.c b/test/battle/ability/neutralizing_gas.c
index 6338bfbeca..f83e928c4a 100644
--- a/test/battle/ability/neutralizing_gas.c
+++ b/test/battle/ability/neutralizing_gas.c
@@ -256,7 +256,8 @@ SINGLE_BATTLE_TEST("Neutralizing Gas prevents Trace from copying it")
 SINGLE_BATTLE_TEST("Neutralizing Gas prevents Contrary inverting stat boosts")
 {
     GIVEN {
-        ASSUME(GetMoveEffect(MOVE_REST) == EFFECT_REST);
+        ASSUME(GetMoveEffect(MOVE_SWORDS_DANCE) == EFFECT_ATTACK_UP_2);
+        ASSUME(GetMoveEffect(MOVE_LEER) == EFFECT_DEFENSE_DOWN);
         PLAYER(SPECIES_INKAY) { Ability(ABILITY_CONTRARY); }
         OPPONENT(SPECIES_WEEZING) { Ability(ABILITY_NEUTRALIZING_GAS); }
     } WHEN {
@@ -271,3 +272,41 @@ SINGLE_BATTLE_TEST("Neutralizing Gas prevents Contrary inverting stat boosts")
         EXPECT_LT(player->statStages[STAT_DEF], DEFAULT_STAT_STAGE);
     }
 }
+
+SINGLE_BATTLE_TEST("Neutralizing Gas exiting the field does not activate abilities that were not suppressed by it again")
+{
+    u32 species, ability;
+    // These are the only abilities that could immediately activate again
+    PARAMETRIZE { species = SPECIES_KOMALA; ability = ABILITY_COMATOSE; }
+    PARAMETRIZE { species = SPECIES_CALYREX_SHADOW; ability = ABILITY_AS_ONE_SHADOW_RIDER; }
+    PARAMETRIZE { species = SPECIES_CALYREX_ICE; ability = ABILITY_AS_ONE_ICE_RIDER; }
+
+    GIVEN {
+        ASSUME(gAbilitiesInfo[ability].cantBeSuppressed);
+        PLAYER(species) { Ability(ability); }
+        OPPONENT(SPECIES_WEEZING) { Ability(ABILITY_NEUTRALIZING_GAS); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { SWITCH(opponent, 1); }
+    } SCENE {
+        ABILITY_POPUP(player, ability);
+        MESSAGE("The effects of the neutralizing gas wore off!");
+        NOT ABILITY_POPUP(player, ability);
+    }
+}
+
+SINGLE_BATTLE_TEST("Neutralizing Gas exiting the field does not activate Imposter even if it did not activate before")
+{
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET);
+        PLAYER(SPECIES_DITTO) { Ability(ABILITY_IMPOSTER); }
+        OPPONENT(SPECIES_WEEZING) { Ability(ABILITY_NEUTRALIZING_GAS); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { SWITCH(player, 1); SWITCH(opponent, 1); }
+    } SCENE {
+        NOT ABILITY_POPUP(player, ABILITY_IMPOSTER);
+        MESSAGE("The effects of the neutralizing gas wore off!");
+        NOT ABILITY_POPUP(player, ABILITY_IMPOSTER);
+    }
+}