diff --git a/src/pow.ts b/src/pow.ts
index 2e89f08..dbd594b 100644
--- a/src/pow.ts
+++ b/src/pow.ts
@@ -14,11 +14,13 @@ const determineDifficulty = () => {
 const determineChallengesNeeded = (amount: number, usedCaptcha: boolean) => {
   const { MIN_TEZ, MAX_TEZ, MIN_CHALLENGES, MAX_CHALLENGES, MAX_CHALLENGES_WITH_CAPTCHA } = env
 
-  // Calculate the proportion of the requested Tez to the maximum Tez
-  const tezProportion = (amount - MIN_TEZ) / (MAX_TEZ - MIN_TEZ)
-
   // Calculate the base number of challenges based on the Tez proportion and whether a captcha was used
   const maxChallenges = usedCaptcha ? MAX_CHALLENGES_WITH_CAPTCHA : MAX_CHALLENGES
+
+  if (MIN_TEZ === MAX_TEZ) return maxChallenges
+
+  // Calculate the proportion of the requested Tez to the maximum Tez
+  const tezProportion = (amount - MIN_TEZ) / (MAX_TEZ - MIN_TEZ)
   const challengesNeeded = Math.ceil(tezProportion * (maxChallenges - MIN_CHALLENGES) + MIN_CHALLENGES)
 
   return challengesNeeded