diff --git a/src/battle_util.c b/src/battle_util.c
index 8adee1946f..4f0ffcf962 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -8183,10 +8183,20 @@ static inline u32 CalcMoveBasePower(struct DamageCalculationData *damageCalcData
         basePower = sSpeedDiffPowerTable[speed];
         break;
     case EFFECT_GYRO_BALL:
-        basePower = ((25 * GetBattlerTotalSpeedStat(battlerDef)) / GetBattlerTotalSpeedStat(battlerAtk)) + 1;
-        if (basePower > 150)
-            basePower = 150;
-        break;
+        {
+            u32 attackerSpeed = GetBattlerTotalSpeedStat(battlerAtk);
+            if (attackerSpeed == 0)
+            {
+                basePower = 1;
+            }
+            else
+            {
+                basePower = ((25 * GetBattlerTotalSpeedStat(battlerDef)) / attackerSpeed) + 1;
+                if (basePower > 150)
+                    basePower = 150;
+            }
+            break;
+        }
     case EFFECT_ECHOED_VOICE:
         // gBattleStruct->sameMoveTurns incremented in ppreduce
         if (gBattleStruct->sameMoveTurns[battlerAtk] != 0)