diff --git a/tools/releasetools/edify_generator.py b/tools/releasetools/edify_generator.py
index e4b9252..7d318a3 100644
--- a/tools/releasetools/edify_generator.py
+++ b/tools/releasetools/edify_generator.py
@@ -323,6 +323,10 @@
     """Append text verbatim to the output script."""
     self.script.append(extra)
 
+  def Unmount(self, mount_point):
+    self.script.append('unmount("%s");' % (mount_point,))
+    self.mounts.remove(mount_point);
+
   def UnmountAll(self):
     for p in sorted(self.mounts):
       self.script.append('unmount("%s");' % (p,))