diff --git a/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java b/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
index 6449a848b6f..133c20411fb 100644
--- a/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
+++ b/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
@@ -138,7 +138,7 @@ public class ClusterBlock implements Streamable, ToXContent {
         retryable = in.readBoolean();
         disableStatePersistence = in.readBoolean();
         status = RestStatus.readFrom(in);
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
             allowReleaseResources = in.readBoolean();
         } else {
             allowReleaseResources = false;
@@ -156,7 +156,7 @@ public class ClusterBlock implements Streamable, ToXContent {
         out.writeBoolean(retryable);
         out.writeBoolean(disableStatePersistence);
         RestStatus.writeTo(out, status);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
             out.writeBoolean(allowReleaseResources);
         }
     }