diff --git a/cfg/wxwidgets.cfg b/cfg/wxwidgets.cfg
index bdb161f83..15f5dfe31 100644
--- a/cfg/wxwidgets.cfg
+++ b/cfg/wxwidgets.cfg
@@ -509,8 +509,8 @@
   <define name="IMPLEMENT_APP_NO_MAIN(appname)" value=""/>
   <!-- Override macros which don't necessarily require semicolons at the end -->
   <define name="WXUNUSED(n)" value=""/>
-  <define name="wxDELETE(ptr)" value="{ delete ptr; ptr = NULL; }"/>
-  <define name="wxDELETEA(ptr)" value="{ delete [] ptr; ptr = NULL; }"/>
+  <define name="wxDELETE(ptr)" value="{ delete ptr; ptr = nullptr; }"/>
+  <define name="wxDELETEA(ptr)" value="{ delete [] ptr; ptr = nullptr; }"/>
   <define name="WXDLLIMPEXP_FWD_CORE" value=""/>
   <define name="WXDLLIMPEXP_FWD_BASE" value=""/>
   <define name="WXDLLIMPEXP_CORE" value=""/>
@@ -4850,7 +4850,7 @@
   <define name="wxPG_PROP_BEING_DELETED" value="0x00200000"/>
   <define name="wxPG_PROP_CLASS_SPECIFIC_3" value="0x00400000"/>
   <define name="wxPG_PROP_MAX" value="wxPG_PROP_AUTO_UNSPECIFIED"/>
-  <define name="wxNullProperty" value="((wxPGProperty*)NULL)"/>
+  <define name="wxNullProperty" value="((wxPGProperty*)nullptr)"/>
   <define name="wxPG_ATTR_DEFAULT_VALUE" value="wxS(&quot;DefaultValue&quot;)"/>
   <define name="wxPG_ATTR_MIN" value="wxS(&quot;Min&quot;)"/>
   <define name="wxPG_ATTR_MAX" value="wxS(&quot;Max&quot;)"/>