diff --git a/template/runner-docker-autoscaler-config.tftpl b/template/runner-docker-autoscaler-config.tftpl
index fa6f2cdb..68f6c1cb 100644
--- a/template/runner-docker-autoscaler-config.tftpl
+++ b/template/runner-docker-autoscaler-config.tftpl
@@ -3,8 +3,8 @@
     plugin = "fleeting-plugin-aws"
 
     capacity_per_instance = ${runners_capacity_per_instance}
-    update_interval = ${runners_update_interval}
-    update_interval_when_expecting = ${runners_update_interval_when_expecting}
+    update_interval = "${runners_update_interval}"
+    update_interval_when_expecting = "${runners_update_interval_when_expecting}"
 
     max_use_count = ${runners_max_use_count}
     max_instances = ${runners_max_instances}