diff --git a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineForkchoiceUpdated.java b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineForkchoiceUpdated.java
index 1cde6c259a0..b64fca8d429 100644
--- a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineForkchoiceUpdated.java
+++ b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineForkchoiceUpdated.java
@@ -69,7 +69,8 @@ public AbstractEngineForkchoiceUpdated(
   }
 
   protected ValidationResult<RpcErrorType> validateParameter(
-      final EngineForkchoiceUpdatedParameter forkchoiceUpdatedParameter) {
+      final EngineForkchoiceUpdatedParameter forkchoiceUpdatedParameter,
+      final Optional<EnginePayloadAttributesParameter> maybePayloadAttributes) {
     return ValidationResult.valid();
   }
 
@@ -85,21 +86,21 @@ public JsonRpcResponse syncResponse(final JsonRpcRequestContext requestContext)
         requestContext.getOptionalParameter(1, EnginePayloadAttributesParameter.class);
 
     LOG.debug("Forkchoice parameters {}", forkChoice);
+    ValidationResult<RpcErrorType> parameterValidationResult =
+        validateParameter(forkChoice, maybePayloadAttributes);
+    if (!parameterValidationResult.isValid()) {
+      return new JsonRpcErrorResponse(requestId, parameterValidationResult);
+    }
 
     if (maybePayloadAttributes.isPresent()) {
       final EnginePayloadAttributesParameter payloadAttributes = maybePayloadAttributes.get();
       ValidationResult<RpcErrorType> forkValidationResult =
           validateForkSupported(payloadAttributes.getTimestamp());
       if (!forkValidationResult.isValid()) {
-        return new JsonRpcSuccessResponse(requestId, forkValidationResult);
+        return new JsonRpcErrorResponse(requestId, forkValidationResult);
       }
     }
 
-    ValidationResult<RpcErrorType> parameterValidationResult = validateParameter(forkChoice);
-    if (!parameterValidationResult.isValid()) {
-      return new JsonRpcSuccessResponse(requestId, parameterValidationResult);
-    }
-
     mergeContext
         .get()
         .fireNewUnverifiedForkchoiceEvent(
diff --git a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineGetPayload.java b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineGetPayload.java
index 5cb72d0cb82..a714b25d8b4 100644
--- a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineGetPayload.java
+++ b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineGetPayload.java
@@ -22,7 +22,6 @@
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.methods.ExecutionEngineJsonRpcMethod;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcErrorResponse;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcResponse;
-import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcSuccessResponse;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.RpcErrorType;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.results.BlockResultFactory;
 import org.hyperledger.besu.ethereum.core.BlockHeader;
@@ -79,7 +78,7 @@ public JsonRpcResponse syncResponse(final JsonRpcRequestContext request) {
       ValidationResult<RpcErrorType> forkValidationResult =
           validateForkSupported(proposal.getHeader().getTimestamp());
       if (!forkValidationResult.isValid()) {
-        return new JsonRpcSuccessResponse(request.getRequest().getId(), forkValidationResult);
+        return new JsonRpcErrorResponse(request.getRequest().getId(), forkValidationResult);
       }
       return createResponse(request, payloadId, proposal);
     }
diff --git a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV3.java b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV3.java
index 31dc738fa39..2d25e12cefd 100644
--- a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV3.java
+++ b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV3.java
@@ -18,6 +18,7 @@
 import org.hyperledger.besu.ethereum.ProtocolContext;
 import org.hyperledger.besu.ethereum.api.jsonrpc.RpcMethod;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.parameters.EngineForkchoiceUpdatedParameter;
+import org.hyperledger.besu.ethereum.api.jsonrpc.internal.parameters.EnginePayloadAttributesParameter;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.RpcErrorType;
 import org.hyperledger.besu.ethereum.mainnet.ProtocolSchedule;
 import org.hyperledger.besu.ethereum.mainnet.ScheduledProtocolSpec;
@@ -48,7 +49,8 @@ public String getName() {
 
   @Override
   protected ValidationResult<RpcErrorType> validateParameter(
-      final EngineForkchoiceUpdatedParameter fcuParameter) {
+      final EngineForkchoiceUpdatedParameter fcuParameter,
+      final Optional<EnginePayloadAttributesParameter> maybePayloadAttributes) {
     if (fcuParameter.getHeadBlockHash() == null) {
       return ValidationResult.invalid(RpcErrorType.INVALID_PARAMS, "Missing head block hash");
     } else if (fcuParameter.getSafeBlockHash() == null) {
@@ -56,6 +58,12 @@ protected ValidationResult<RpcErrorType> validateParameter(
     } else if (fcuParameter.getFinalizedBlockHash() == null) {
       return ValidationResult.invalid(RpcErrorType.INVALID_PARAMS, "Missing finalized block hash");
     }
+    if (maybePayloadAttributes.isPresent()) {
+      if (maybePayloadAttributes.get().getParentBeaconBlockRoot() == null) {
+        return ValidationResult.invalid(
+            RpcErrorType.INVALID_PARAMS, "Missing parent beacon block root hash");
+      }
+    }
     return ValidationResult.valid();
   }