diff --git a/build.sh b/build.sh
index 41628b5ba..ace6ae66a 100755
--- a/build.sh
+++ b/build.sh
@@ -101,11 +101,12 @@ FILE=.buildtools
 OS_NAME=`uname -a`
 if [ ! -f $FILE ]; then
   case "$OS_NAME" in
-    *Darwin*) tools/setup-buildtools-apple.sh $MAC_ARCH ;;
-    *Linux*)  [[ -z "$NOROOT" ]] && sudo tools/setup-buildtools.sh || echo "No root: skipping build tools installation." ;;
-    *)        echo "WARNING: unsupported OS $OS_NAME , skipping build tools installation.."
+    *Darwin*) CMD="tools/setup-buildtools-apple.sh $MAC_ARCH" ;;
+    *Linux*)  CMD="tools/setup-buildtools.sh" ;;
+    *)        echo "WARNING: unsupported OS $OS_NAME, skipping build tools installation.." && exit 1 ;;
   esac
-  # Assume that the build tools have been successfully installed
+  
+  [[ -z "$NOROOT" ]] && sudo $CMD || $CMD
   echo > $FILE
 fi