diff --git a/src/stub/Makefile b/src/stub/Makefile
index ff68c57d..0f48be0c 100644
--- a/src/stub/Makefile
+++ b/src/stub/Makefile
@@ -9,6 +9,7 @@
 MAKEFLAGS += -rR
 .SUFFIXES:
 .SECONDEXPANSION:
+.NOTPARALLEL:
 export LC_ALL = C
 export SHELL = /bin/sh