diff --git a/puppet/services/database/mongodb.yaml b/puppet/services/database/mongodb.yaml
index dcead0f7af..dad1148435 100644
--- a/puppet/services/database/mongodb.yaml
+++ b/puppet/services/database/mongodb.yaml
@@ -95,7 +95,11 @@ outputs:
             # internal_api -> IP
             # internal_api_uri -> [IP]
             # internal_api_subnet - > IP/CIDR
-            mongodb::server::bind_ip: {get_param: [ServiceNetMap, MongodbNetwork]}
+            mongodb_bind_ip: {get_param: [ServiceNetMap, MongodbNetwork]}
+            # NOTE: This now takes an array, so we need to fetch the IP from hiera,
+            # else Heat won't substitute the network name for the IP.
+            mongodb::server::bind_ip:
+              - "%{hiera('mongodb_bind_ip')}"
           -
             if:
               - internal_tls_enabled