diff --git a/OWNERS b/OWNERS
index f12e957471..ead150ca8a 100644
--- a/OWNERS
+++ b/OWNERS
@@ -3,6 +3,7 @@ approvers:
 - gsunner
 - cliveseldon
 - ryandawsonuk
+- adriangonz
 reviewers:
 - axsaucedo
 - gsunner
diff --git a/engine/src/main/java/io/seldon/engine/api/rest/RestClientController.java b/engine/src/main/java/io/seldon/engine/api/rest/RestClientController.java
index 8cb08cd178..642aa5b1eb 100644
--- a/engine/src/main/java/io/seldon/engine/api/rest/RestClientController.java
+++ b/engine/src/main/java/io/seldon/engine/api/rest/RestClientController.java
@@ -245,7 +245,7 @@ private ResponseEntity<String> _predictions(String json)
 					throw new APIException(ApiExceptionType.ENGINE_EXECUTION_FAILURE,e.getMessage());
 				}
 			} catch (InvalidProtocolBufferException e) {
-				throw new APIException(ApiExceptionType.ENGINE_INVALID_JSON,"");
+				throw new APIException(ApiExceptionType.ENGINE_INVALID_RESPONSE_JSON,"");
 			}
 	}
 
@@ -292,7 +292,7 @@ public ResponseEntity<String>  feedback(RequestEntity<String> requestEntity) {
 				throw new APIException(ApiExceptionType.ENGINE_EXECUTION_FAILURE,e.getMessage());
 			}
 		} catch (InvalidProtocolBufferException e) {
-			throw new APIException(ApiExceptionType.ENGINE_INVALID_JSON,"");
+			throw new APIException(ApiExceptionType.ENGINE_INVALID_RESPONSE_JSON,"");
 		} 
 		}
 		finally
diff --git a/engine/src/main/java/io/seldon/engine/exception/APIException.java b/engine/src/main/java/io/seldon/engine/exception/APIException.java
index 8c8af4bda0..d8a7130baa 100644
--- a/engine/src/main/java/io/seldon/engine/exception/APIException.java
+++ b/engine/src/main/java/io/seldon/engine/exception/APIException.java
@@ -27,7 +27,8 @@ public class APIException extends RuntimeException {
 
 	public enum ApiExceptionType { 
 		
-		ENGINE_INVALID_JSON(201,"Invalid JSON",500),
+		ENGINE_INVALID_JSON(201,"Invalid JSON",400),
+		ENGINE_INVALID_RESPONSE_JSON(201,"Invalid Response JSON",500),
 		ENGINE_INVALID_ENDPOINT_URL(202,"Invalid Endpoint URL",500),	
 		ENGINE_MICROSERVICE_ERROR(203,"Microservice error",500),
 		ENGINE_INVALID_ABTEST(204,"Error happened in AB Test Routing",500),