diff --git a/src/com/mirantis/mk/Openstack.groovy b/src/com/mirantis/mk/Openstack.groovy
index 1d79ea3..1cf5d57 100644
--- a/src/com/mirantis/mk/Openstack.groovy
+++ b/src/com/mirantis/mk/Openstack.groovy
@@ -7,6 +7,15 @@
  */
 
 /**
+ * Convert maps
+ *
+ */
+
+@NonCPS def entries(m) {
+    return m.collect {k, v -> [k, v]}
+}
+
+/**
  * Install OpenStack service clients in isolated environment
  *
  * @param path        Path where virtualenv is created
@@ -121,7 +130,7 @@
         envString = "parameters:\n"
     }
 
-    def p = environment.collect {k, v -> [k, v]}
+    p = entries(environment)
     for (int i = 0; i < p.size(); i++) {
         envString = "${envString}  ${p.get(i)[0]}: ${p.get(i)[1]}\n"
     }