diff --git a/src/main/java/org/jenkinsci/plugins/envinject/EnvInjectPluginAction.java b/src/main/java/org/jenkinsci/plugins/envinject/EnvInjectPluginAction.java
index 2c1a67a4..24f7c2d9 100644
--- a/src/main/java/org/jenkinsci/plugins/envinject/EnvInjectPluginAction.java
+++ b/src/main/java/org/jenkinsci/plugins/envinject/EnvInjectPluginAction.java
@@ -22,7 +22,8 @@ public Object getTarget() {
         return new EnvInjectVarList(Maps.transformEntries(envMap,
                 new Maps.EntryTransformer<String, String, String>() {
                     public String transformEntry(String key, String value) {
-                        return getSensibleVariables() != null && getSensibleVariables().contains(key) ? "********" : value;
+                        final Set<String> sensibleVars = getSensibleVariables();
+                        return sensibleVars != null && sensibleVars.contains(key) ? "********" : value;
                     }
                 }));
     }