diff --git a/Makefile b/Makefile
index ae36c66b41..cbc57f593f 100644
--- a/Makefile
+++ b/Makefile
@@ -253,7 +253,7 @@ export LANG = C
 export LC_ALL = C
 export GZIP = -n
 BR2_VERSION_GIT_EPOCH = $(shell GIT_DIR=$(TOPDIR)/.git $(GIT) log -1 --format=%at)
-export SOURCE_DATE_EPOCH = $(if $(wildcard $(TOPDIR)/.git),$(BR2_VERSION_GIT_EPOCH),$(BR2_VERSION_EPOCH))
+export SOURCE_DATE_EPOCH ?= $(if $(wildcard $(TOPDIR)/.git),$(BR2_VERSION_GIT_EPOCH),$(BR2_VERSION_EPOCH))
 DEPENDENCIES_HOST_PREREQ += host-fakedate
 endif