diff --git a/buildSrc/src/main/groovy/org/elasticsearch/gradle/test/ClusterFormationTasks.groovy b/buildSrc/src/main/groovy/org/elasticsearch/gradle/test/ClusterFormationTasks.groovy
index 90c839720fb7f..d6eeb2f444713 100644
--- a/buildSrc/src/main/groovy/org/elasticsearch/gradle/test/ClusterFormationTasks.groovy
+++ b/buildSrc/src/main/groovy/org/elasticsearch/gradle/test/ClusterFormationTasks.groovy
@@ -351,8 +351,9 @@ class ClusterFormationTasks {
             String key = entry.getKey()
             String name = taskName(parent, node, 'addToKeystore#' + key)
             Task t = configureExecTask(name, project, parentTask, node, esKeystoreUtil, 'add', key, '-x')
+            String settingsValue = entry.getValue() // eval this early otherwise it will not use the right value
             t.doFirst {
-                standardInput = new ByteArrayInputStream(entry.getValue().getBytes(StandardCharsets.UTF_8))
+                standardInput = new ByteArrayInputStream(settingsValue.getBytes(StandardCharsets.UTF_8))
             }
             parentTask = t
         }