diff --git a/lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/SerializableObject.java b/lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/SerializableObject.java
index ee108a4dfe7..fa8005e99eb 100644
--- a/lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/SerializableObject.java
+++ b/lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/SerializableObject.java
@@ -422,7 +422,7 @@ public interface SerializableObject {
    * @param value is the value to write.
    */
   static void writeBoolean(final OutputStream outputStream, final boolean value) throws IOException {
-    outputStream.write(value?0:1);
+    outputStream.write(value?1:0);
   }
   
   /** Read a boolean from a stream.