diff --git a/lib/plugins/aws/package/compile/layers/index.js b/lib/plugins/aws/package/compile/layers/index.js
index fd4a36e14..8404e2197 100644
--- a/lib/plugins/aws/package/compile/layers/index.js
+++ b/lib/plugins/aws/package/compile/layers/index.js
@@ -56,6 +56,10 @@ class AwsCompileLayers {
 
     if (layerObject.allowedAccounts) {
       layerObject.allowedAccounts.map(account => {
+        // cast to string if account is number
+        if(typeof account == 'number' && !isNaN(account)) {
+          account = `${account}`;
+        }
         const newPermission = this.cfLambdaLayerPermissionTemplate();
         newPermission.Properties.LayerVersionArn = { Ref: layerLogicalId };
         newPermission.Properties.Principal = account;