diff --git a/src/data/ability.ts b/src/data/ability.ts
index 6b0eb24a4b9..92655713468 100644
--- a/src/data/ability.ts
+++ b/src/data/ability.ts
@@ -249,10 +249,10 @@ export class PreDefendFormChangeAbAttr extends PreDefendAbAttr {
 }
 export class PreDefendFullHpEndureAbAttr extends PreDefendAbAttr {
   applyPreDefend(pokemon: Pokemon, passive: boolean, attacker: Pokemon, move: PokemonMove, cancelled: Utils.BooleanHolder, args: any[]): boolean {
-    if (pokemon.hp === pokemon.getMaxHp() && (args[0] as Utils.NumberHolder).value >= pokemon.hp){ //Checks if pokemon hp is full and if the damage is higher or equal to defender hp
+    if (pokemon.hp === pokemon.getMaxHp() && pokemon.getMaxHp() >= 1 && (args[0] as Utils.NumberHolder).value >= pokemon.hp){ //Checks if pokemon hp is full and if the damage is higher or equal to defender hp
       return pokemon.addTag(BattlerTagType.STURDY, 1); //activates sturdy
     } else {
-      return
+      return false
     } 
   }
 }