diff --git a/makefiles/consts.mk b/makefiles/consts.mk
index 4e3e24d..bac4362 100644
--- a/makefiles/consts.mk
+++ b/makefiles/consts.mk
@@ -30,8 +30,9 @@
 # [DEBUG] make {target} HIDE=
 HIDE        ?= @
 
-env-clean   = /usr/bin/env --ignore-environment
-xargs-n1    := xargs -0 -t -n1 --no-run-if-empty
+env-clean      ?= /usr/bin/env --ignore-environment
+xargs-n1       := xargs -0 -t -n1 --no-run-if-empty
+xargs-n1-clean := $(env-clean) $(xargs-n1)
 
 ## -----------------------------------------------------------------------
 ## Default shell:
@@ -44,6 +45,8 @@
 $(if $(have-shell-bash),$(null),\
   $(eval export SHELL := bash -euo pipefail))
 
+export SHELL ?= bash -euo pipefail
+
 $(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]