diff --git a/ApplicationCode/Commands/RicEclipsePropertyFilterFeatureImpl.h b/ApplicationCode/Commands/RicEclipsePropertyFilterFeatureImpl.h
index 2a69b6a3c7..c8d0b1a37a 100644
--- a/ApplicationCode/Commands/RicEclipsePropertyFilterFeatureImpl.h
+++ b/ApplicationCode/Commands/RicEclipsePropertyFilterFeatureImpl.h
@@ -20,6 +20,7 @@
 #pragma once
 
 #include <vector>
+#include <cstddef>
 
 class RimEclipsePropertyFilter;
 class RimEclipsePropertyFilterCollection;
diff --git a/ApplicationCode/Commands/RicGeoMechPropertyFilterFeatureImpl.h b/ApplicationCode/Commands/RicGeoMechPropertyFilterFeatureImpl.h
index bd445367b8..877617e6da 100644
--- a/ApplicationCode/Commands/RicGeoMechPropertyFilterFeatureImpl.h
+++ b/ApplicationCode/Commands/RicGeoMechPropertyFilterFeatureImpl.h
@@ -20,6 +20,7 @@
 #pragma once
 
 #include <vector>
+#include <cstddef>
 
 class RimGeoMechPropertyFilter;
 class RimGeoMechPropertyFilterCollection;