diff --git a/docs/insecure.md b/docs/insecure.md
index 7d4ea3175..9ccb54196 100644
--- a/docs/insecure.md
+++ b/docs/insecure.md
@@ -78,9 +78,13 @@ Usually, on Ubuntu this is done with:
     cp auth/domain.crt /usr/local/share/ca-certificates/myregistrydomain.com.crt
     update-ca-certificates
 
-... and on RedHat with:
+... and on Red Hat (and its derivatives) with:
 
     cp auth/domain.crt /etc/pki/ca-trust/source/anchors/myregistrydomain.com.crt
     update-ca-trust
 
+... On some distributions, e.g. Oracle Linux 6, the Shared System Certificates feature needs to be manually enabled:
+
+    update-ca-trust enable
+
 Now restart docker (`service docker stop && service docker start`, or any other way you use to restart docker).