diff --git a/calc/src/mechanics/gen4.ts b/calc/src/mechanics/gen4.ts
index 59c1aac9d..656ef34b5 100644
--- a/calc/src/mechanics/gen4.ts
+++ b/calc/src/mechanics/gen4.ts
@@ -144,8 +144,9 @@ export function calculateDPP(
 
   let typeEffectiveness = type1Effectiveness * type2Effectiveness;
 
-  // Iron Ball ignores Klutz in generation 4
-  if (typeEffectiveness === 0 && move.hasType('Ground') && defender.hasItem('Iron Ball')) {
+  // Klutz doesn't let Iron Ball ground in generation 4
+  if (typeEffectiveness === 0 && move.hasType('Ground') &&
+    (defender.hasItem('Iron Ball') && !defender.hasAbility('Klutz'))) {
     if (type1Effectiveness === 0) {
       type1Effectiveness = 1;
     } else if (defender.types[1] && type2Effectiveness === 0) {
diff --git a/calc/src/mechanics/util.ts b/calc/src/mechanics/util.ts
index 7ff91b9c7..e707d60b0 100644
--- a/calc/src/mechanics/util.ts
+++ b/calc/src/mechanics/util.ts
@@ -190,9 +190,11 @@ export function checkForecast(pokemon: Pokemon, weather?: Weather) {
 }
 
 export function checkItem(pokemon: Pokemon, magicRoomActive?: boolean) {
+  // Pokemon with Klutz still get their speed dropped in generation 4
+  if (pokemon.gen.num === 4 && pokemon.hasItem('Iron Ball')) return;
   if (
     pokemon.hasAbility('Klutz') && !EV_ITEMS.includes(pokemon.item!) ||
-      magicRoomActive
+    magicRoomActive
   ) {
     pokemon.item = '' as ItemName;
   }