diff --git a/tasks/setup-Debian.yml b/tasks/setup-Debian.yml
index 9d292d1..db56ce9 100644
--- a/tasks/setup-Debian.yml
+++ b/tasks/setup-Debian.yml
@@ -28,4 +28,4 @@
   apt:
     name: "{{ varnish_modules_package_name }}"
     state: present
-  when: varnish_modules_package_name
+  when: varnish_modules_package_name|length
diff --git a/tasks/setup-RedHat.yml b/tasks/setup-RedHat.yml
index 946cca1..eea5cf9 100644
--- a/tasks/setup-RedHat.yml
+++ b/tasks/setup-RedHat.yml
@@ -46,4 +46,4 @@
   yum:
     name: "{{ varnish_modules_package_name }}"
     state: present
-  when: varnish_modules_package_name
+  when: varnish_modules_package_name is defined and varnish_modules_package_name|length > 0