diff --git a/beacon/engine/types.go b/beacon/engine/types.go
index d474ffe1d9..d8f66163ba 100644
--- a/beacon/engine/types.go
+++ b/beacon/engine/types.go
@@ -336,7 +336,7 @@ func BlockToExecutableData(block *types.Block, fees *big.Int, sidecars []*types.
 		for j := range sidecar.Blobs {
 			bundle.Blobs = append(bundle.Blobs, hexutil.Bytes(sidecar.Blobs[j][:]))
 			bundle.Commitments = append(bundle.Commitments, hexutil.Bytes(sidecar.Commitments[j][:]))
-			if len(sidecar.Proofs[j]) != 0 {
+			if len(sidecar.CellProofs[j]) == 0 {
 				bundle.Proofs = append(bundle.Proofs, hexutil.Bytes(sidecar.Proofs[j][:]))
 			} else {
 				for _, proof := range sidecar.CellProofs[j] {