diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index ffcd38b..536d47f 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1015,7 +1015,7 @@
   return ramdisk_img
 
 
-def _BuildBootableImage(sourcedir, fs_config_file, info_dict=None,
+def _BuildBootableImage(image_name, sourcedir, fs_config_file, info_dict=None,
                         has_ramdisk=False, two_step_image=False):
   """Build a bootable image from the specified sourcedir.
 
@@ -1028,7 +1028,15 @@
   for building the requested image.
   """
 
-  if not os.access(os.path.join(sourcedir, "kernel"), os.F_OK):
+  # "boot" or "recovery", without extension.
+  partition_name = os.path.basename(sourcedir).lower()
+
+  if partition_name == "recovery":
+    kernel = "kernel"
+  else:
+    kernel = image_name.replace("boot", "kernel")
+    kernel = kernel.replace(".img","")
+  if not os.access(os.path.join(sourcedir, kernel), os.F_OK):
     return None
 
   if has_ramdisk and not os.access(os.path.join(sourcedir, "RAMDISK"), os.F_OK):
@@ -1045,7 +1053,7 @@
   # use MKBOOTIMG from environ, or "mkbootimg" if empty or not set
   mkbootimg = os.getenv('MKBOOTIMG') or "mkbootimg"
 
-  cmd = [mkbootimg, "--kernel", os.path.join(sourcedir, "kernel")]
+  cmd = [mkbootimg, "--kernel", os.path.join(sourcedir, kernel)]
 
   fn = os.path.join(sourcedir, "second")
   if os.access(fn, os.F_OK):
@@ -1072,9 +1080,6 @@
     cmd.append("--pagesize")
     cmd.append(open(fn).read().rstrip("\n"))
 
-  # "boot" or "recovery", without extension.
-  partition_name = os.path.basename(sourcedir).lower()
-
   if partition_name == "recovery":
     args = info_dict.get("recovery_mkbootimg_args")
   else:
@@ -1197,7 +1202,7 @@
                  info_dict.get("recovery_as_boot") == "true")
 
   fs_config = "META/" + tree_subdir.lower() + "_filesystem_config.txt"
-  data = _BuildBootableImage(os.path.join(unpack_dir, tree_subdir),
+  data = _BuildBootableImage(prebuilt_name, os.path.join(unpack_dir, tree_subdir),
                              os.path.join(unpack_dir, fs_config),
                              info_dict, has_ramdisk, two_step_image)
   if data: