diff --git a/scripts/multiple-clients.sh b/scripts/multiple-clients.sh
index 18d61875..2439cc3c 100755
--- a/scripts/multiple-clients.sh
+++ b/scripts/multiple-clients.sh
@@ -14,6 +14,7 @@
 #
 
 set -e
+umask 0077
 LIBDIR=~/bochslibs
 
 # cleanup earlier failures