diff --git a/CHANGELOG.md b/CHANGELOG.md
index 796fc50..76d3e32 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Changelog
 
+## Quantum Mobile v19.XX.0
+
+### Improvements
+* now installing fixed versions of ansible roles for improved reproducibility
+  and tracking of changes between Quantum Mobile releases
+
+### Software updates
+* roles:
+  * marvel-nccr.add_user v0.2.1
+  * marvel-nccr.simulationbase v0.1.1
+
+### Build process
+ * Virtualbox v6.0.8
+
 ## Quantum Mobile v19.03.0
 
 ### Improvements
diff --git a/README.md b/README.md
index 4cb8d8b..f4c6c12 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ provenance tracking.
 You can run Quantum Mobile on your Windows, MacOS or Linux computer using the
 [VirtualBox](http://virtualbox.org/) software.
 You can also
-[install Quantum Mobile on virtual machines using cloud services](https://github.com/materialscloud-org/ansible-playbook-workhorse)
+[install Quantum Mobile on virtual machines using cloud services](https://github.com/marvel-nccr/ansible-playbook-workhorse)
 like Amazon Web Services or OpenStack.
 
 ![Demo](https://image.ibb.co/n50SdT/quantum_mobile.gif "A brief impression of the Quantum Mobile interface.")
diff --git a/globalconfig.yml b/globalconfig.yml
index 6903628..5c39fac 100644
--- a/globalconfig.yml
+++ b/globalconfig.yml
@@ -1,7 +1,7 @@
 ---
 # Caution: This file is read by vagrant, ansible and bash
-vm_version: "19.03.0"
 vm_name: "Quantum Mobile"
+vm_version: "19.05.0-tutorial"
 vm_description: "A Virtual Machine for Computational Materials Science"
 vm_url: "https://github.com/marvel-nccr/marvel-virtualmachine"
 vm_author: "MARVEL NCCR and MaX CoE"
diff --git a/playbook.yml b/playbook.yml
index bd2bfe2..85ae37b 100644
--- a/playbook.yml
+++ b/playbook.yml
@@ -3,11 +3,14 @@
   hosts: default
   gather_facts: no
   roles:
-    - marvel-nccr.ansible_prerequisites
+    - role: marvel-nccr.ansible_prerequisites
 
+# Note: This play could be merged with "set up the VM" but it can make sense to
+# connect to the VM using the user created here. Leaving it separate for the moment.
 - name: Add vm user
   hosts: default
   gather_facts: no
+  tags: add_user
   pre_tasks:
     - name: import global variables
       tags: always
@@ -25,7 +28,10 @@
       vars:
         add_user_name: "{{ vm_user }}"
         add_user_password: "{{ vm_password }}"
-        add_user_sudo: True
+        add_user_groups:
+          - "{{ vm_user }}"
+          - sudo
+        add_user_passwordless_sudo: true
          
 # Note: it is important to pass variables to roles using the 'vars' dictionary.
 # If variables are passed on the same indentation level as the role, the variable is
@@ -35,11 +41,6 @@
   hosts: default
   become: True
   become_user: "{{ vm_user }}"
-  pre_tasks:
-    - name: import global variables
-      tags: always
-      include_vars:
-        file: globalconfig.yml
   vars:
     - release_notes: True
     - run_tests: False
@@ -80,11 +81,6 @@
         slurm_hostname: "{{ vm_hostname }}"
         slurm_cpus: "{{ vm_cpus }}"
         slurm_memory: "{{ vm_memory }}"
-#    - role: marvel-nccr.torque
-#      tags: torque
-#      vars:
-#        torque_hostname: "{{ vm_hostname }}"
-#        torque_cpus: "{{ vm_cpus }}"
     - role: marvel-nccr.quantum_espresso
       tags: quantum_espresso
       vars: 
@@ -109,6 +105,10 @@
       tags: wannier90
       vars: 
         wannier90_code_folder: "{{ vm_codes_folder }}"
+    - role: marvel-nccr.aiidalab
+      tags: aiidalab
+      vars:
+        aiidalab_headless: "{{ vm_headless }}"
     - role: marvel-nccr.aiida
       tags: aiida 
       vars:
@@ -116,7 +116,3 @@
         aiida_localhost_cpus: "{{ vm_cpus }}"
         aiida_localhost_scheduler: "{{ vm_scheduler }}"
         aiida_examples_folder: "{{ vm_examples_folder }}"
-    - role: marvel-nccr.aiidalab
-      tags: aiidalab
-      vars:
-        aiidalab_headless: "{{ vm_headless }}"
diff --git a/requirements.yml b/requirements.yml
index 0cc3eac..baba474 100644
--- a/requirements.yml
+++ b/requirements.yml
@@ -4,34 +4,40 @@
 #- src: gantsign.default-web-browser
 #  version: 3.1.0
 - src: marvel-nccr.ansible_prerequisites
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.current_user
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.add_user
-  version: master
+  version: v0.2.1
 - src: marvel-nccr.simulationbase
-  version: master
+  version: v0.1.1
 - src: marvel-nccr.ubuntu_desktop
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.quantum_mobile_customizations
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.editors
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.slurm
-  version: master
+  version: v0.1.1
 - src: marvel-nccr.quantum_espresso
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.yambo
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.fleur
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.siesta
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.cp2k
-  version: master
+  version: v0.1.0
 - src: marvel-nccr.wannier90
-  version: master
-- src: marvel-nccr.aiida
-  version: master
-- src: marvel-nccr.aiidalab
-  version: master
+  version: v0.1.0
+#- src: marvel-nccr.aiida
+#  version: v0.1.0
+- src: https://github.com/marvel-nccr/ansible-role-aiida.git
+  version: tutorial-2019-05
+  name: marvel-nccr.aiida
+#- src: marvel-nccr.aiidalab
+#  version: v0.1.0
+- src: https://github.com/marvel-nccr/ansible-role-aiidalab.git
+  version: tutorial-2019-05
+  name: marvel-nccr.aiidalab