diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index ffda6cf..927d89a 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -27,6 +27,8 @@
 import commands
 import shutil
 
+import simg_map
+
 def RunCommand(cmd):
   """ Echo and run the given command
 
@@ -146,6 +148,13 @@
     return False, None
   return True, unsparse_image_path
 
+def MappedUnsparseImage(sparse_image_path, unsparse_image_path,
+                        map_path, mapped_unsparse_image_path):
+  if simg_map.ComputeMap(sparse_image_path, unsparse_image_path,
+                         map_path, mapped_unsparse_image_path):
+    return False
+  return True
+
 def MakeVerityEnabledImage(out_file, prop_dict):
   """Creates an image that is verifiable using dm-verity.