diff --git a/ApplicationLibCode/Commands/HoloLensCommands/VdeCachingHashedIdFactory.h b/ApplicationLibCode/Commands/HoloLensCommands/VdeCachingHashedIdFactory.h
index 87516f3f08..fe33f44546 100644
--- a/ApplicationLibCode/Commands/HoloLensCommands/VdeCachingHashedIdFactory.h
+++ b/ApplicationLibCode/Commands/HoloLensCommands/VdeCachingHashedIdFactory.h
@@ -18,6 +18,7 @@
 
 #pragma once
 
+#include <cstddef>
 #include <cstdint>
 
 #include <map>
diff --git a/ApplicationLibCode/ReservoirDataModel/RigAccWellFlowCalculator.h b/ApplicationLibCode/ReservoirDataModel/RigAccWellFlowCalculator.h
index 030a10f396..814fb327fb 100644
--- a/ApplicationLibCode/ReservoirDataModel/RigAccWellFlowCalculator.h
+++ b/ApplicationLibCode/ReservoirDataModel/RigAccWellFlowCalculator.h
@@ -17,8 +17,11 @@
 /////////////////////////////////////////////////////////////////////////////////
 
 #pragma once
+
+#include <cstddef>
 #include <map>
 #include <vector>
+
 //==================================================================================================
 ///
 ///