diff --git a/dropshell-tool/build.sh b/dropshell-tool/build.sh
index 0375159..1cd8a10 100755
--- a/dropshell-tool/build.sh
+++ b/dropshell-tool/build.sh
@@ -4,6 +4,7 @@ set -euo pipefail
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 
 TEMP_DIR=$(mktemp -d)
+trap 'rm -rf "${TEMP_DIR}"' EXIT
 
 function getbin() {
     local BIN_NAME="$1"
@@ -14,6 +15,7 @@ function getbin() {
 
 getbin "dropshell-build"
 
+rm -rf "${SCRIPT_DIR}/build"
+
 "${TEMP_DIR}/dropshell-build" -r -m "${SCRIPT_DIR}" 
 
-rm -rf "${TEMP_DIR}"