--- src/VBox/Runtime/Makefile.kmk.orig	2024-11-20 20:11:05.667725000 +0100
+++ src/VBox/Runtime/Makefile.kmk	2024-11-20 20:12:40.904599000 +0100
@@ -220,6 +220,9 @@
 	$(QUIET)$(oiddb2c_1_TARGET) "$@" $(filter %.cfg,$^)
 	$(QUIET)$(CP) --changed -fv "$@" "$(IPRT_OUT_DIR)/oiddb.h"
 
+# Set the defines that utf8-posix.cpp needs. It's used by several targets.
+#
+r3/posix/utf8-posix.cpp_DEFS.freebsd = $(VBOX_ICONV_DEFS)
 
 #
 # Unicode Specification reader used to regenerate unidata-*.cpp.