diff --git a/src/requesthandler/types/RequestBatchExecutionType.h b/src/requesthandler/types/RequestBatchExecutionType.h
index d778ee99..df158ffe 100644
--- a/src/requesthandler/types/RequestBatchExecutionType.h
+++ b/src/requesthandler/types/RequestBatchExecutionType.h
@@ -22,7 +22,7 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 #include <stdint.h>
 
 namespace RequestBatchExecutionType {
-	enum RequestBatchExecutionType {
+	enum RequestBatchExecutionType: int8_t {
 		/**
 		* Not a request batch.
 		*
@@ -77,7 +77,7 @@ namespace RequestBatchExecutionType {
 		Parallel = 2,
 	};
 
-	inline bool IsValid(int executionType)
+	inline bool IsValid(int8_t executionType)
 	{
 		return executionType >= None && executionType <= Parallel;
 	}
diff --git a/src/websocketserver/WebSocketServer_Protocol.cpp b/src/websocketserver/WebSocketServer_Protocol.cpp
index 689ef977..67c082c3 100644
--- a/src/websocketserver/WebSocketServer_Protocol.cpp
+++ b/src/websocketserver/WebSocketServer_Protocol.cpp
@@ -233,7 +233,7 @@ void WebSocketServer::ProcessMessage(SessionPtr session, WebSocketServer::Proces
 					return;
 				}
 
-				uint8_t requestedExecutionType = payloadData["executionType"];
+				int8_t requestedExecutionType = payloadData["executionType"];
 				if (!RequestBatchExecutionType::IsValid(requestedExecutionType) || requestedExecutionType == RequestBatchExecutionType::None) {
 					ret.closeCode = WebSocketCloseCode::InvalidDataFieldValue;
 					ret.closeReason = "Your `executionType` has an invalid value.";