lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java b/lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java
index 7038a2e..c4b2f7e 100644
--- a/lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java
+++ b/lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java
@@ -163,7 +163,8 @@ public class MMapDirectory extends FSDirectory {
   /**
    * <code>true</code>, if this platform supports unmapping mmapped files.
    */
-  public static final boolean UNMAP_SUPPORTED = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
+  public static final boolean UNMAP_SUPPORTED = (Constants.JRE_IS_MINIMUM_JAVA9 == false)
+    && AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
     @Override
     @SuppressForbidden(reason = "Java 9 Jigsaw whitelists access to sun.misc.Cleaner, so setAccessible works")
     public Boolean run() {