diff --git a/Makefile b/Makefile
index 6a0bfd7..c36248b 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 # Makefile for testing JJB jobs in a virtualenv
 .PHONY: test clean
 
-SHELL = bash -e -o pipefail
+SHELL         := bash -e -o pipefail
 VENV_DIR      ?= venv-jjb
 JJB_VERSION   ?= 4.1.0
 JOBCONFIG_DIR ?= job-configs