diff --git a/core/definitions.mk b/core/definitions.mk
index 4739204..c97f647 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2480,12 +2480,15 @@
 
 # Copies many files.
 # $(1): The files to copy.  Each entry is a ':' separated src:dst pair
+# $(2): An optional directory to prepend to the destination
 # Evaluates to the list of the dst files (ie suitable for a dependency list)
 define copy-many-files
 $(foreach f, $(1), $(strip \
     $(eval _cmf_tuple := $(subst :, ,$(f))) \
     $(eval _cmf_src := $(word 1,$(_cmf_tuple))) \
     $(eval _cmf_dest := $(word 2,$(_cmf_tuple))) \
+    $(if $(strip $(2)), \
+      $(eval _cmf_dest := $(patsubst %/,%,$(strip $(2)))/$(patsubst /%,%,$(_cmf_dest)))) \
     $(if $(filter-out $(_cmf_src), $(_cmf_dest)), \
       $(eval $(call copy-one-file,$(_cmf_src),$(_cmf_dest)))) \
     $(_cmf_dest)))