diff --git a/lib/portage_util.py b/lib/portage_util.py
index 57d1e2f..ea9b75d 100644
--- a/lib/portage_util.py
+++ b/lib/portage_util.py
@@ -537,26 +537,35 @@
     is_stable = False
     is_blacklisted = False
     has_test = False
-    for line in fileinput.input(ebuild_path):
-      if line.startswith('inherit '):
-        eclasses = set(line.split())
-        if 'cros-workon' in eclasses:
-          is_workon = True
-        if EBuild._ECLASS_IMPLIES_TEST & eclasses:
+    with open(ebuild_path, mode='rb') as fp:
+      for i, line in enumerate(fp):
+        # If the file has bad encodings, produce a helpful diagnostic for the
+        # user.  The default encoding exception lacks direct file context.
+        try:
+          line = line.decode('utf-8')
+        except UnicodeDecodeError:
+          logging.exception('%s: line %i: invalid UTF-8: %s',
+                            ebuild_path, i, line)
+          raise
+
+        if line.startswith('inherit '):
+          eclasses = set(line.split())
+          if 'cros-workon' in eclasses:
+            is_workon = True
+          if EBuild._ECLASS_IMPLIES_TEST & eclasses:
+            has_test = True
+        elif line.startswith('KEYWORDS='):
+          # Strip off the comments, then extract the value of the variable, then
+          # strip off any quotes.
+          line = line.split('#', 1)[0].split('=', 1)[1].strip('"\'')
+          for keyword in line.split():
+            if not keyword.startswith('~') and keyword != '-*':
+              is_stable = True
+        elif line.startswith('CROS_WORKON_BLACKLIST='):
+          is_blacklisted = True
+        elif (line.startswith('src_test()') or
+              line.startswith('platform_pkg_test()')):
           has_test = True
-      elif line.startswith('KEYWORDS='):
-        # Strip off the comments, then extract the value of the variable, then
-        # strip off any quotes.
-        line = line.split('#', 1)[0].split('=', 1)[1].strip('"\'')
-        for keyword in line.split():
-          if not keyword.startswith('~') and keyword != '-*':
-            is_stable = True
-      elif line.startswith('CROS_WORKON_BLACKLIST='):
-        is_blacklisted = True
-      elif (line.startswith('src_test()') or
-            line.startswith('platform_pkg_test()')):
-        has_test = True
-    fileinput.close()
     return EBuildClassifyAttributes(
         is_workon, is_stable, is_blacklisted, has_test)
 
diff --git a/lib/portage_util_unittest.py b/lib/portage_util_unittest.py
index cca890f..7f0685d 100644
--- a/lib/portage_util_unittest.py
+++ b/lib/portage_util_unittest.py
@@ -281,6 +281,30 @@
       attrs = portage_util.EBuild.Classify(ebuild_path)
       self.assertTrue(attrs.is_stable, msg='Failing: %s' % (keywords,))
 
+  def testClassifyEncodingASCII(self):
+    """Test Classify with ASCII file encodings."""
+    ebuild_path = os.path.join(self.tempdir, 'foo-1.ebuild')
+    # Generate a valid shell script with all possible ASCII values.
+    osutils.WriteFile(
+        ebuild_path,
+        'cat <<\\EOF\n%s\nEOF\n' % (''.join(chr(x) for x in range(0, 128)),))
+    # Just check that we don't throw an exception.
+    portage_util.EBuild.Classify(ebuild_path)
+
+  def testClassifyEncodingUTF8(self):
+    """Test Classify with UTF-8 file encodings."""
+    ebuild_path = os.path.join(self.tempdir, 'foo-1.ebuild')
+    osutils.WriteFile(ebuild_path, '# FöÖßbäłł')
+    # Just check that we don't throw an exception.
+    portage_util.EBuild.Classify(ebuild_path)
+
+  def testClassifyEncodingLatin1(self):
+    """Test Classify with ISO 8859-1 file encodings."""
+    ebuild_path = os.path.join(self.tempdir, 'foo-1.ebuild')
+    osutils.WriteFile(ebuild_path, b'# This is \xa0 bad UTF-8', mode='wb')
+    with self.assertRaises(UnicodeDecodeError):
+      portage_util.EBuild.Classify(ebuild_path)
+
 
 class ProjectAndPathTest(cros_test_lib.MockTempDirTestCase):
   """Project and Path related tests."""