diff --git a/compiler/systems/i_amiga.pas b/compiler/systems/i_amiga.pas
index 415032244c..02d3711389 100644
--- a/compiler/systems/i_amiga.pas
+++ b/compiler/systems/i_amiga.pas
@@ -99,7 +99,7 @@ unit i_amiga;
             flags        : [tf_files_case_aware];
             cpu          : cpu_powerpc;
             unit_env     : '';
-            extradefines : 'PPC603;HASAMIGA';
+            extradefines : 'PPC603;HASAMIGA;AMIGAOS4';
             exeext       : '';
             defext       : '.def';
             scriptext    : '.sh';