diff --git a/INSTALL.d/INSTALL.Ubuntu.txt b/INSTALL.d/INSTALL.Ubuntu.txt
index 38e9781..bfe9d8d 100644
--- a/INSTALL.d/INSTALL.Ubuntu.txt
+++ b/INSTALL.d/INSTALL.Ubuntu.txt
@@ -29,6 +29,7 @@ libtest-pod-perl \
 libtest-simple-perl     \
 libunicode-string-perl \
 liburi-perl \
+libtest-mockobject-perl \
 cpanminus
 
 The second command installs "manually" the Perl module Data::Uniqid