diff --git a/Makefile b/Makefile
index ed0917c37..26b3ddd98 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,9 @@
 
 #-----------------------------------------------
 
+BASH_EXISTS := $(shell which bash)
+SHELL := $(shell which bash)
+
 CLEAN_FILES = # deliberately empty, so we can append below.
 CFLAGS += ${EXTRA_CFLAGS}
 CXXFLAGS += ${EXTRA_CXXFLAGS}