diff --git a/src/java.base/share/classes/java/nio/file/Files.java b/src/java.base/share/classes/java/nio/file/Files.java
index 82ab732aec4..cc35012fa0a 100644
--- a/src/java.base/share/classes/java/nio/file/Files.java
+++ b/src/java.base/share/classes/java/nio/file/Files.java
@@ -1359,6 +1359,9 @@ public final class Files {
      *     associated with a different provider to this object. </td>
      * </tbody>
      * </table>
+     * If the {@code ATOMIC_MOVE} option is not specified, then the check
+     * whether the target file exists and the actual move might not be atomic
+     * with respect to other filesystem activities.
      *
      * <p> An implementation of this interface may support additional
      * implementation specific options.
@@ -1404,8 +1407,11 @@ public final class Files {
      *          if the array contains a copy option that is not supported
      * @throws  FileAlreadyExistsException
      *          if the target file exists but cannot be replaced because the
-     *          {@code REPLACE_EXISTING} option is not specified <i>(optional
-     *          specific exception)</i>
+     *          {@code REPLACE_EXISTING} option is <i>not</i> specified.
+     *          It may also be thrown when the {@code REPLACE_EXISTING} option
+     *          <i>is</i> specified, the move is not atomic, and the target
+     *          file is created by some other entity at around the same time
+     *          that this method is called
      * @throws  DirectoryNotEmptyException
      *          the {@code REPLACE_EXISTING} option is specified but the file
      *          cannot be replaced because it is a non-empty directory, or the