diff --git a/dtool/pptempl/compilerSettings.pp b/dtool/pptempl/compilerSettings.pp
index bb4eec2d3e..0a58c5ff34 100644
--- a/dtool/pptempl/compilerSettings.pp
+++ b/dtool/pptempl/compilerSettings.pp
@@ -79,6 +79,9 @@
   #define COMPILER icl
   #define LINKER xilink
   #define LIBBER xilib
+  
+  #define CDEFINES_OPT4 UNKNOWN_ALLOCATOR  
+  
   #define COMMONFLAGS /Gi- /Qwd985
 //  #define OPTFLAGS /O3 /G6 /Qvc6 /Qipo /QaxW /Qvec_report1 
   #define OPTFLAGS /O3 /G6 /Qvc6 /Qip /QIfist