diff --git a/cppadcodegen/depend.mk b/cppadcodegen/depend.mk
index 75b10efb2c872d4a3250397bb352321df5856e5f..ca18a91a71c97414eae4410385ff7c731a9b360a 100644
--- a/cppadcodegen/depend.mk
+++ b/cppadcodegen/depend.mk
@@ -11,6 +11,10 @@ endif
 
 ifeq (+,$(CPPADCODEGEN_DEPEND_MK)) # ------------------------------------------
 
+include ../../mk/robotpkg.prefs.mk # for OPSYS
+ifeq (Arch,${OPSYS})
+  PREFER.cppadcodegen?=	system
+endif
 PREFER.cppadcodegen?=	robotpkg
 
 SYSTEM_SEARCH.cppadcodegen=\