diff --git a/tools/releasetools/test_build_image.py b/tools/releasetools/test_build_image.py
index 1cebd0c..b24805f 100644
--- a/tools/releasetools/test_build_image.py
+++ b/tools/releasetools/test_build_image.py
@@ -18,12 +18,13 @@
 import os.path
 
 import common
+import test_utils
 from build_image import (
-    BuildImageError, CheckHeadroom, GetFilesystemCharacteristics, SetUpInDirAndFsConfig)
-from test_utils import ReleaseToolsTestCase
+    BuildImageError, CheckHeadroom, GetFilesystemCharacteristics,
+    SetUpInDirAndFsConfig)
 
 
-class BuildImageTest(ReleaseToolsTestCase):
+class BuildImageTest(test_utils.ReleaseToolsTestCase):
 
   # Available: 1000 blocks.
   EXT4FS_OUTPUT = (
@@ -48,6 +49,7 @@
     self.assertRaises(
         BuildImageError, CheckHeadroom, self.EXT4FS_OUTPUT, prop_dict)
 
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_CheckHeadroom_WrongFsType(self):
     prop_dict = {
         'fs_type' : 'f2fs',
@@ -72,6 +74,7 @@
     self.assertRaises(
         AssertionError, CheckHeadroom, self.EXT4FS_OUTPUT, prop_dict)
 
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_CheckHeadroom_WithMke2fsOutput(self):
     """Tests the result parsing from actual call to mke2fs."""
     input_dir = common.MakeTempDir()
@@ -177,13 +180,14 @@
     self.assertIn('fs-config-root\n', fs_config_data)
     self.assertEqual('/', prop_dict['mount_point'])
 
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_GetFilesystemCharacteristics(self):
     input_dir = common.MakeTempDir()
     output_image = common.MakeTempFile(suffix='.img')
     command = ['mkuserimg_mke2fs', input_dir, output_image, 'ext4',
                '/system', '409600', '-j', '0']
     proc = common.Run(command)
-    ext4fs_output, _ = proc.communicate()
+    proc.communicate()
     self.assertEqual(0, proc.returncode)
 
     output_file = common.MakeTempFile(suffix='.img')