-AC_PATH_PROG([PGREP], [pgrep], [no])
-AM_CONDITIONAL([HAVE_PGREP], [test "x$PGREP" != "xno"])
+AC_PATH_PROG([PGREP], [pgrep])
+AM_CONDITIONAL([HAVE_PGREP], [test "x$PGREP" != "x"])
+
+AC_PATH_PROG([SHELLCHECK], [shellcheck])
+AM_CONDITIONAL([HAVE_SHELLCHECK], [test "x$SHELLCHECK" != "x"])