diff --git a/tasks/configure.yml b/tasks/configure.yml
index 0cfcd09..1cd84a4 100644
--- a/tasks/configure.yml
+++ b/tasks/configure.yml
@@ -20,7 +20,9 @@
 - name: Set command for opendkim-genkey (using where)
   set_fact:
     opendkim_genkey_cmd: "{{ where_result.stdout }}"
-  when: where_result.stdout != ''
+  when:
+    - stdout in where_result
+    - where_result.stdout != ''
 
 - name: Fail if opendkim-genkey is not found
   fail: