diff --git a/packages/numlib/src/typ.pas b/packages/numlib/src/typ.pas
index 36bd65ac2c..d62a82ef54 100644
--- a/packages/numlib/src/typ.pas
+++ b/packages/numlib/src/typ.pas
@@ -43,15 +43,16 @@ unit typ;
 {$I DIRECT.INC}                 {Contains "global" compilerswitches which
                                   are imported into every unit of the library }
 
-{$if sizeof(extended)=10}
-{$DEFINE ArbExtended}
-{$endif}
 
 interface
 
 uses
   Math;
 
+{$if sizeof(extended)=10}
+{$DEFINE ArbExtended}
+{$endif}
+
 
 CONST numlib_version=2;         {used to detect version conflicts between
                                   header unit and dll}