diff --git a/packages/base/amd64/upgrade/builds/Makefile b/packages/base/amd64/upgrade/builds/Makefile
index 04e6d11b..772ff62f 100644
--- a/packages/base/amd64/upgrade/builds/Makefile
+++ b/packages/base/amd64/upgrade/builds/Makefile
@@ -1,14 +1,15 @@
 include $(ONL)/make/config.amd64.mk
 
-# All amd64 kernels
-KERNELS := $(shell $(ONLPM) --find-file onl-kernel-3.16-lts-x86-64-all:amd64 kernel-3.16-lts-x86_64-all) \
-	   $(shell $(ONLPM) --find-file onl-kernel-4.9-lts-x86-64-all:amd64 kernel-4.9-lts-x86_64-all) \
-	   $(shell $(ONLPM) --find-file onl-kernel-4.14-lts-x86-64-all:amd64 kernel-4.14-lts-x86_64-all)
+$(eval $(call onlpm_find_file,KERNEL_3_16,onl-kernel-3.16-lts-x86-64-all:amd64,kernel-3.16-lts-x86_64-all))
+$(eval $(call onlpm_find_file,KERNEL_4_9,onl-kernel-4.9-lts-x86-64-all:amd64,kernel-4.9-lts-x86_64-all))
+$(eval $(call onlpm_find_file,KERNEL_4_14,onl-kernel-4.14-lts-x86-64-all:amd64,kernel-4.14-lts-x86_64-all))
 
+# All amd64 kernels
+KERNELS := $(KERNEL_3_16) $(KERNEL_4_9) $(KERNEL_4_14)
 
 # Loader initrd
-INITRD := $(shell $(ONLPM) --find-file onl-loader-initrd:amd64 onl-loader-initrd-amd64.cpio.gz)
-MANIFEST := $(shell $(ONLPM) --find-file onl-loader-initrd:amd64 manifest.json)
+$(eval $(call onlpm_find_file,INITRD,onl-loader-initrd:amd64,onl-loader-initrd-amd64.cpio.gz))
+$(eval $(call onlpm_find_file,MANIFEST,onl-loader-initrd:amd64,manifest.json))
 
 all:
 	mkdir -p files