diff --git a/sdk/src/sl_lidar_driver.cpp b/sdk/src/sl_lidar_driver.cpp
index 1e7e234..f596855 100644
--- a/sdk/src/sl_lidar_driver.cpp
+++ b/sdk/src/sl_lidar_driver.cpp
@@ -553,10 +553,10 @@ namespace sl {
         {
             switch (_dataEvt.wait(timeout))
             {
-            case rp::hal::Event::EVENT_TIMEOUT:
+            case (unsigned long int)rp::hal::Event::EVENT_TIMEOUT:
                 count = 0;
                 return SL_RESULT_OPERATION_TIMEOUT;
-            case rp::hal::Event::EVENT_OK:
+            case (unsigned long int)rp::hal::Event::EVENT_OK:
             {
                 if (_cached_scan_node_hq_count == 0) return SL_RESULT_OPERATION_TIMEOUT; //consider as timeout
 
@@ -1984,4 +1984,4 @@ namespace sl {
     {
         return new SlamtecLidarDriver();
     }
-}
\ No newline at end of file
+}