diff --git a/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip b/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip
index 0d4faa83..f7e98851 100755
--- a/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip
+++ b/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip
@@ -110,12 +110,13 @@ else
     # pre-install packages so dependencies are there.  We will
     # overwrite with latest below.
     packages="python-pip python3-pip python-virtualenv"
-    # unfortunately older ubuntu (trusty) doesn't have a
+
+    # Unfortunately older ubuntu (trusty) doesn't have a
     # python3-virtualenv package -- it seems it wasn't ready at the
     # time and you had to use "python -m venv".  Since then virtualenv
     # has gained 3.4 support so the pip install below will work
     if [[ ${DIB_PYTHON_VERSION} == 3 ]]; then
-        packages=$(echo "$packages" | sed s/python-virtualenv/python3-virtualenv/)
+        packages+=" python3-virtualenv"
     fi
 
     apt-get -y install $packages