diff --git a/overcloud.j2.yaml b/overcloud.j2.yaml
index fbcd7a4cdd..95e7682f5d 100644
--- a/overcloud.j2.yaml
+++ b/overcloud.j2.yaml
@@ -317,7 +317,7 @@ resources:
   HorizonSecret:
     type: OS::TripleO::RandomString
     properties:
-      length: 10
+      length: 64
 
   NetCidrMapValue:
     type: OS::Heat::Value