diff --git a/build b/build
index 80c5bcb..454e87b 100755
--- a/build
+++ b/build
@@ -36,13 +36,13 @@ build_docker() {
 }
 
 # if an arg is specified, force building with the specified method
-[ $1 ] && build_$1 && exit
+[ $1 ] && (build_$1; exit)
 
 # prefer building with local go install if it exists on path
 if which go &> /dev/null; then
   build_go; exit
 # if windows or linux, try building with docker
-elif echo $os | grep -e linux -e windows; then
+elif echo $os | grep -qe linux -e windows; then
   which docker &> /dev/null && (build_docker; exit)
 fi