diff --git a/build b/build
index 37f209e8b57..d644addce84 100755
--- a/build
+++ b/build
@@ -41,4 +41,4 @@ etcd_build() {
 toggle_failpoints
 
 # don't build when sourced
-(echo "$0" | grep "/build$") && etcd_build || true
+(echo "$0" | grep "/build$" > /dev/null) && etcd_build || true