diff --git a/linux/linux.mk b/linux/linux.mk
index 06792382a9..bdd8bb3e44 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -23,7 +23,7 @@ LINUX_VERSION_MINOR = $(word 2,$(subst ., ,$(subst -, ,$(LINUX_VERSION))))
 LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v$(LINUX_VERSION_MAJOR).$(LINUX_VERSION_MINOR)/
 # release candidates are in testing/ subdir
 ifneq ($(findstring -rc,$(LINUX_VERSION)),)
-LINUX_SITE = $(LINUX_SITE)testing/
+LINUX_SITE := $(LINUX_SITE)testing/
 endif # -rc
 endif