diff --git a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/helpers/MiscHelpers.java b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/helpers/MiscHelpers.java
index 027752c6965..3eb9549d551 100644
--- a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/helpers/MiscHelpers.java
+++ b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/helpers/MiscHelpers.java
@@ -123,7 +123,7 @@ public UInt64 computeStartSlotAtEpoch(final UInt64 epoch) {
   }
 
   public UInt64 computeEndSlotAtEpoch(final UInt64 epoch) {
-    return computeStartSlotAtEpoch(epoch.plus(1)).minusMinZero(1);
+    return computeStartSlotAtEpoch(epoch).plus(specConfig.getSlotsPerEpoch() - 1);
   }
 
   public UInt64 computeSlotAtTime(final UInt64 genesisTime, final UInt64 currentTime) {