diff --git a/targets/Makerules b/targets/Makerules
index ccbe13ba75..5387a3b335 100644
--- a/targets/Makerules
+++ b/targets/Makerules
@@ -9,8 +9,8 @@ export PWD
 
 OBJS_DIR := $(PWD)/objs
 
-SVN_REV = $(shell svnversion -n .)
-DATE_REV = $(shell date '+%F %T')
+SVN_REV := $(shell svnversion -n .)
+DATE_REV := $(shell date '+%F %T')
 
 NUM_CORES=$(shell cat /proc/cpuinfo | grep processor | wc -l)