diff --git a/roles/mgrote.apt_manage_sources/tasks/main.yml b/roles/mgrote.apt_manage_sources/tasks/main.yml
index 8d5272f3..494ac87e 100644
--- a/roles/mgrote.apt_manage_sources/tasks/main.yml
+++ b/roles/mgrote.apt_manage_sources/tasks/main.yml
@@ -3,16 +3,16 @@
     include_tasks: ubuntu.yml
     when:
       - ansible_distribution == 'Ubuntu'
-      - manage_sources_apt_proxy | length > 0
+      - manage_sources_apt_proxy is defined
 
   - name: include Linux Mint tasks (determined by "ansible_distribution")
     include_tasks: mint.yml
     when:
       - ansible_distribution == 'Linux Mint'
-      - manage_sources_apt_proxy | length > 0
+      - manage_sources_apt_proxy is defined
 
   - name: include proxmox tasks (determined by group)
     include_tasks: proxmox.yml
     when:
       - "'proxmox' in group_names"
-      - manage_sources_apt_proxy | length > 0
+      - manage_sources_apt_proxy is defined
diff --git a/roles/mgrote.apt_manage_sources/templates/apt.conf b/roles/mgrote.apt_manage_sources/templates/apt.conf
index 495e5e87..7c98d3a5 100644
--- a/roles/mgrote.apt_manage_sources/templates/apt.conf
+++ b/roles/mgrote.apt_manage_sources/templates/apt.conf
@@ -1,3 +1,5 @@
 {{ file_header | default () }}
+{% if manage_sources_apt_proxy | length > 0 %}
 Acquire::http::proxy "http://{{ manage_sources_apt_proxy | default() }}";
 Acquire::https::proxy "http://{{ manage_sources_apt_proxy | default() }}";
+{% endif %}