diff --git a/packages/beacon-node/src/api/impl/validator/index.ts b/packages/beacon-node/src/api/impl/validator/index.ts
index 9c5e6c2987f1..1fccf083070c 100644
--- a/packages/beacon-node/src/api/impl/validator/index.ts
+++ b/packages/beacon-node/src/api/impl/validator/index.ts
@@ -957,6 +957,8 @@ export function getValidatorApi(
           break;
 
         case stateEpoch + 1:
+          // make sure shuffling is calculated and ready for next call to calculate nextProposers
+          await chain.shufflingCache.get(state.epochCtx.nextEpoch, state.epochCtx.nextDecisionRoot);
           // Requesting duties for next epoch is allowed since they can be predicted with high probabilities.
           // @see `epochCtx.getBeaconProposersNextEpoch` JSDocs for rationale.
           indexes = state.epochCtx.getBeaconProposersNextEpoch();
diff --git a/packages/state-transition/src/cache/epochCache.ts b/packages/state-transition/src/cache/epochCache.ts
index 4eb16fa49927..5601162b2c2a 100644
--- a/packages/state-transition/src/cache/epochCache.ts
+++ b/packages/state-transition/src/cache/epochCache.ts
@@ -921,7 +921,7 @@ export class EpochCache {
   getBeaconProposersNextEpoch(): ValidatorIndex[] {
     if (!this.proposersNextEpoch.computed) {
       const indexes = computeProposers(
-        this.config.getForkSeqAtEpoch(this.epoch + 1),
+        this.config.getForkSeqAtEpoch(this.nextEpoch),
         this.proposersNextEpoch.seed,
         this.getShufflingAtEpoch(this.nextEpoch),
         this.effectiveBalanceIncrements