diff --git a/test/fs/fs.sh b/test/fs/fs.sh
index b49e447b7fb..381fe31d508 100755
--- a/test/fs/fs.sh
+++ b/test/fs/fs.sh
@@ -46,8 +46,11 @@ echo "TESTING: read/write /var/tmp (test/fs/fs_var_tmp.exp)"
 rm -f /var/tmp/_firejail_test_file
 
 if [ "$(uname -m)" = "x86_64" ]; then
+    fjconfig=/etc/firejail/firejail.config
+    printf 'private-lib yes\n' >> "$fjconfig"
     echo "TESTING: private-lib (test/fs/private-lib.exp)"
     ./private-lib.exp
+    printf '%s\n' "$(sed '/^private-lib yes$/d' "$fjconfig")" > "$fjconfig"
 else
     echo "TESTING SKIP: private-lib test implemented only for x86_64."
 fi