diff --git a/REFERENCE.md b/REFERENCE.md
index 76d672ff..d76a0586 100644
--- a/REFERENCE.md
+++ b/REFERENCE.md
@@ -1352,6 +1352,12 @@ Data type: `Optional[Boolean]`
 
 If true, run Puppet in no-op mode
 
+##### `in_progress_timeout`
+
+Data type: `Integer[1]`
+
+How many seconds to wait for a puppet run, that is already in progress
+
 ### <a name="rbac_token"></a>`rbac_token`
 
 Get and save an rbac token for the root user, admin rbac user
diff --git a/tasks/puppet_runonce.json b/tasks/puppet_runonce.json
index 0be93712..087b60fe 100644
--- a/tasks/puppet_runonce.json
+++ b/tasks/puppet_runonce.json
@@ -8,6 +8,11 @@
     "noop": {
       "type": "Optional[Boolean]",
       "description": "If true, run Puppet in no-op mode"
+    },
+    "in_progress_timeout": {
+      "type": "Integer[1]",
+      "description": "How many seconds to wait for a puppet run, that is already in progress",
+      "default": 600
     }
   },
   "input_method": "environment",
diff --git a/tasks/puppet_runonce.sh b/tasks/puppet_runonce.sh
index fe08a946..1e72c86a 100755
--- a/tasks/puppet_runonce.sh
+++ b/tasks/puppet_runonce.sh
@@ -15,7 +15,7 @@
 echo -n "Check for and wait up to 5 minutes for in-progress run to complete"
 lockfile=$(/opt/puppetlabs/bin/puppet config print agent_catalog_run_lockfile)
 n=0
-until [ $n -ge 300 ]
+until [ $n -ge "$PT_in_progress_timeout" ]
 do
   [ ! -e "$lockfile" ] && break
   echo -n .