diff --git a/tools/dtoc/test_fdt.py b/tools/dtoc/test_fdt.py
index ed2d982..16a4430 100755
--- a/tools/dtoc/test_fdt.py
+++ b/tools/dtoc/test_fdt.py
@@ -9,7 +9,9 @@
 from optparse import OptionParser
 import glob
 import os
+import shutil
 import sys
+import tempfile
 import unittest
 
 # Bring in the patman libraries
@@ -540,10 +542,23 @@
         self.assertEqual(0x12345678, fdt_util.fdt_cells_to_cpu(val, 1))
 
     def testEnsureCompiled(self):
-        """Test a degenerate case of this function"""
+        """Test a degenerate case of this function (file already compiled)"""
         dtb = fdt_util.EnsureCompiled('tools/dtoc/dtoc_test_simple.dts')
         self.assertEqual(dtb, fdt_util.EnsureCompiled(dtb))
 
+    def testEnsureCompiledTmpdir(self):
+        """Test providing a temporary directory"""
+        try:
+            old_outdir = tools.outdir
+            tools.outdir= None
+            tmpdir = tempfile.mkdtemp(prefix='test_fdt.')
+            dtb = fdt_util.EnsureCompiled('tools/dtoc/dtoc_test_simple.dts',
+                                          tmpdir)
+            self.assertEqual(tmpdir, os.path.dirname(dtb))
+            shutil.rmtree(tmpdir)
+        finally:
+            tools.outdir= old_outdir
+
 
 def RunTestCoverage():
     """Run the tests and check that we get 100% coverage"""