diff --git a/scripts/paycheck.py b/scripts/paycheck.py
index 7fd4b17..245b63e 100755
--- a/scripts/paycheck.py
+++ b/scripts/paycheck.py
@@ -62,6 +62,11 @@
                         help='assert a non-default (4096) payload block size')
   check_opts.add_option('-u', '--allow-unhashed', action='store_true',
                         default=False, help='allow unhashed operations')
+  check_opts.add_option('-d', '--disabled_tests', metavar='TESTLIST',
+                        default=(),
+                        help=('comma-separated list of tests to disable; '
+                              'available values: ' +
+                              ', '.join(update_payload.CHECKS_TO_DISABLE)))
   check_opts.add_option('-k', '--key', metavar='FILE',
                         help='public key to be used for signature verification')
   check_opts.add_option('-m', '--meta-sig', metavar='FILE',
@@ -84,6 +89,13 @@
   if opts.assert_type not in (None, _TYPE_FULL, _TYPE_DELTA):
     parser.error('invalid argument to --type: %s' % opts.assert_type)
 
+  # Convert and validate --disabled_tests value list, if provided.
+  if opts.disabled_tests:
+    opts.disabled_tests = opts.disabled_tests.split(',')
+    for test in opts.disabled_tests:
+      if test not in update_payload.CHECKS_TO_DISABLE:
+        parser.error('invalid argument to --disabled_tests: %s' % test)
+
   # Ensure consistent use of block tracing options.
   do_block_trace = opts.root_block or opts.kern_block
   if opts.skip and not do_block_trace:
@@ -145,7 +157,8 @@
               report_out_file=report_file,
               assert_type=options.assert_type,
               block_size=int(options.block_size),
-              allow_unhashed=options.allow_unhashed)
+              allow_unhashed=options.allow_unhashed,
+              disabled_tests=options.disabled_tests)
         finally:
           if do_close_report_file:
             report_file.close()
diff --git a/scripts/update_payload/__init__.py b/scripts/update_payload/__init__.py
index e437f40..eae23af 100644
--- a/scripts/update_payload/__init__.py
+++ b/scripts/update_payload/__init__.py
@@ -8,3 +8,4 @@
 # pylint: disable=W0401
 from error import PayloadError
 from payload import Payload
+from checker import CHECKS_TO_DISABLE
diff --git a/scripts/update_payload/checker.py b/scripts/update_payload/checker.py
index b85e2b8..703b166 100644
--- a/scripts/update_payload/checker.py
+++ b/scripts/update_payload/checker.py
@@ -28,6 +28,15 @@
 #
 # Constants / helper functions.
 #
+_CHECK_DST_PSEUDO_EXTENTS = 'dst-pseudo-extents'
+_CHECK_MOVE_SAME_SRC_DST_BLOCK = 'move-same-src-dst-block'
+_CHECK_PAYLOAD_SIG = 'payload-sig'
+CHECKS_TO_DISABLE = (
+  _CHECK_DST_PSEUDO_EXTENTS,
+  _CHECK_MOVE_SAME_SRC_DST_BLOCK,
+  _CHECK_PAYLOAD_SIG,
+)
+
 _TYPE_FULL = 'full'
 _TYPE_DELTA = 'delta'
 
@@ -252,19 +261,45 @@
 
   """
 
-  def __init__(self, payload):
+  def __init__(self, payload, assert_type=None, block_size=0,
+               allow_unhashed=False, disabled_tests=()):
+    """Initialize the checker object.
+
+    Args:
+      payload: the payload object to check
+      assert_type: assert that payload is either 'full' or 'delta' (optional)
+      block_size: expected filesystem / payload block size (optional)
+      allow_unhashed: allow operations with unhashed data blobs
+      disabled_tests: list of tests to disable
+
+    """
     assert payload.is_init, 'uninitialized update payload'
+
+    # Set checker configuration.
     self.payload = payload
+    self.block_size = block_size if block_size else _DEFAULT_BLOCK_SIZE
+    if not _IsPowerOfTwo(self.block_size):
+      raise PayloadError('expected block (%d) size is not a power of two' %
+                         self.block_size)
+    if assert_type not in (None, _TYPE_FULL, _TYPE_DELTA):
+      raise PayloadError("invalid assert_type value (`%s')" % assert_type)
+    self.payload_type = assert_type
+    self.allow_unhashed = allow_unhashed
+
+    # Disable specific tests.
+    self.check_dst_pseudo_extents = (
+        _CHECK_DST_PSEUDO_EXTENTS not in disabled_tests)
+    self.check_move_same_src_dst_block = (
+        _CHECK_MOVE_SAME_SRC_DST_BLOCK not in disabled_tests)
+    self.check_payload_sig = _CHECK_PAYLOAD_SIG not in disabled_tests
 
     # Reset state; these will be assigned when the manifest is checked.
-    self.block_size = _DEFAULT_BLOCK_SIZE
     self.sigs_offset = 0
     self.sigs_size = 0
     self.old_rootfs_size = 0
     self.old_kernel_size = 0
     self.new_rootfs_size = 0
     self.new_kernel_size = 0
-    self.payload_type = None
 
   @staticmethod
   def _CheckElem(msg, name, report, is_mandatory, is_submsg, convert=str,
@@ -668,7 +703,7 @@
         dst_idx = dst_extent.start_block
         dst_num = dst_extent.num_blocks
 
-      if src_idx == dst_idx:
+      if self.check_move_same_src_dst_block and src_idx == dst_idx:
         raise PayloadError('%s: src/dst block number %d is the same (%d)' %
                            (op_name, i, src_idx))
 
@@ -716,8 +751,7 @@
 
   def _CheckOperation(self, op, op_name, is_last, old_block_counters,
                       new_block_counters, old_part_size, new_part_size,
-                      prev_data_offset, allow_signature, allow_unhashed,
-                      blob_hash_counts):
+                      prev_data_offset, allow_signature, blob_hash_counts):
     """Checks a single update operation.
 
     Args:
@@ -730,7 +764,6 @@
       new_part_size: the target partition size in bytes
       prev_data_offset: offset of last used data bytes
       allow_signature: whether this may be a signature operation
-      allow_unhashed: allow operations with unhashed data blobs
       blob_hash_counts: counters for hashed/unhashed blobs
     Returns:
       The amount of data blob associated with the operation.
@@ -746,7 +779,9 @@
                                   op.type == common.OpType.REPLACE)
     total_dst_blocks = self._CheckExtents(
         op.dst_extents, new_part_size, new_block_counters,
-        op_name + '.dst_extents', allow_signature=allow_signature_in_extents)
+        op_name + '.dst_extents',
+        allow_pseudo=(not self.check_dst_pseudo_extents),
+        allow_signature=allow_signature_in_extents)
 
     # Check: data_offset present <==> data_length present.
     data_offset = self._CheckOptionalField(op, 'data_offset', None)
@@ -785,7 +820,7 @@
     elif data_offset is not None:
       if allow_signature_in_extents:
         blob_hash_counts['signature'] += 1
-      elif allow_unhashed:
+      elif self.allow_unhashed:
         blob_hash_counts['unhashed'] += 1
       else:
         raise PayloadError('%s: unhashed operation not allowed' % op_name)
@@ -827,8 +862,7 @@
     return array.array('B', [0] * num_blocks)
 
   def _CheckOperations(self, operations, report, base_name, old_part_size,
-                       new_part_size, prev_data_offset, allow_unhashed,
-                       allow_signature):
+                       new_part_size, prev_data_offset, allow_signature):
     """Checks a sequence of update operations.
 
     Args:
@@ -838,7 +872,6 @@
       old_part_size: the old partition size in bytes
       new_part_size: the new partition size in bytes
       prev_data_offset: offset of last used data bytes
-      allow_unhashed: allow operations with unhashed data blobs
       allow_signature: whether this sequence may contain signature operations
     Returns:
       The total data blob size used.
@@ -889,7 +922,7 @@
       curr_data_used = self._CheckOperation(
           op, op_name, is_last, old_block_counters, new_block_counters,
           old_part_size, new_part_size, prev_data_offset + total_data_used,
-          allow_signature, allow_unhashed, blob_hash_counts)
+          allow_signature, blob_hash_counts)
       if curr_data_used:
         op_blob_totals[op.type] += curr_data_used
         total_data_used += curr_data_used
@@ -981,33 +1014,19 @@
         raise PayloadError('unknown signature version (%d)' % sig.version)
 
   def Run(self, pubkey_file_name=None, metadata_sig_file=None,
-          report_out_file=None, assert_type=None, block_size=0,
-          allow_unhashed=False):
+          report_out_file=None):
     """Checker entry point, invoking all checks.
 
     Args:
       pubkey_file_name: public key used for signature verification
       metadata_sig_file: metadata signature, if verification is desired
       report_out_file: file object to dump the report to
-      assert_type: assert that payload is either 'full' or 'delta' (optional)
-      block_size: expected filesystem / payload block size
-      allow_unhashed: allow operations with unhashed data blobs
     Raises:
       PayloadError if payload verification failed.
 
     """
     report = _PayloadReport()
 
-    if assert_type not in (None, _TYPE_FULL, _TYPE_DELTA):
-      raise PayloadError("invalid assert_type value (`%s')" % assert_type)
-    self.payload_type = assert_type
-
-    if block_size:
-      self.block_size = block_size
-    if not _IsPowerOfTwo(self.block_size):
-      raise PayloadError('expected block (%d) size is not a power of two' %
-                         self.block_size)
-
     # Get payload file size.
     self.payload.payload_file.seek(0, 2)
     payload_file_size = self.payload.payload_file.tell()
@@ -1041,15 +1060,15 @@
       report.AddSection('rootfs operations')
       total_blob_size = self._CheckOperations(
           self.payload.manifest.install_operations, report,
-          'install_operations', self.old_rootfs_size,
-          self.new_rootfs_size, 0, allow_unhashed, False)
+          'install_operations', self.old_rootfs_size, self.new_rootfs_size, 0,
+          False)
 
       # Part 4: examine kernel operations.
       report.AddSection('kernel operations')
       total_blob_size += self._CheckOperations(
           self.payload.manifest.kernel_install_operations, report,
           'kernel_install_operations', self.old_kernel_size,
-          self.new_kernel_size, total_blob_size, allow_unhashed, True)
+          self.new_kernel_size, total_blob_size, True)
 
       # Check: operations data reach the end of the payload file.
       used_payload_size = self.payload.data_offset + total_blob_size
@@ -1059,7 +1078,7 @@
             (used_payload_size, payload_file_size))
 
       # Part 5: handle payload signatures message.
-      if self.sigs_size:
+      if self.check_payload_sig and self.sigs_size:
         if not pubkey_file_name:
           raise PayloadError(
               'no public key provided, cannot verify payload signature')
diff --git a/scripts/update_payload/checker_unittest.py b/scripts/update_payload/checker_unittest.py
index 681a920..8d134fc 100755
--- a/scripts/update_payload/checker_unittest.py
+++ b/scripts/update_payload/checker_unittest.py
@@ -54,14 +54,20 @@
   return count << 30
 
 
-def _GetPayloadChecker(payload_gen_write_to_file_func, *largs, **dargs):
+def _GetPayloadChecker(payload_gen_write_to_file_func, payload_gen_dargs=None,
+                       checker_init_dargs=None):
   """Returns a payload checker from a given payload generator."""
+  if payload_gen_dargs is None:
+    payload_gen_dargs = {}
+  if checker_init_dargs is None:
+    checker_init_dargs = {}
+
   payload_file = cStringIO.StringIO()
-  payload_gen_write_to_file_func(payload_file, *largs, **dargs)
+  payload_gen_write_to_file_func(payload_file, **payload_gen_dargs)
   payload_file.seek(0)
   payload = update_payload.Payload(payload_file)
   payload.Init()
-  return checker.PayloadChecker(payload)
+  return checker.PayloadChecker(payload, **checker_init_dargs)
 
 
 def _GetPayloadCheckerWithData(payload_gen):
@@ -783,7 +789,8 @@
 
     # Create the test object.
     payload = self.MockPayload()
-    payload_checker = checker.PayloadChecker(payload)
+    payload_checker = checker.PayloadChecker(payload,
+                                             allow_unhashed=allow_unhashed)
     block_size = payload_checker.block_size
 
     # Create auxiliary arguments.
@@ -865,7 +872,7 @@
                    fail_dst_length or fail_data_hash or fail_prev_data_offset)
     largs = [op, 'foo', is_last, old_block_counters, new_block_counters,
              old_part_size, new_part_size, prev_data_offset, allow_signature,
-             allow_unhashed, blob_hash_counts]
+             blob_hash_counts]
     if should_fail:
       self.assertRaises(update_payload.PayloadError,
                         payload_checker._CheckOperation, *largs)
@@ -919,13 +926,15 @@
                              data_length=rootfs_data_length)
 
     # Create the test object.
-    payload_checker = _GetPayloadChecker(payload_gen.WriteToFile)
+    payload_checker = _GetPayloadChecker(payload_gen.WriteToFile,
+                                         checker_init_dargs={
+                                             'allow_unhashed': True})
     payload_checker.payload_type = checker._TYPE_FULL
     report = checker._PayloadReport()
 
     should_fail = (fail_bad_type or fail_nonexhaustive_full_update)
     largs = (payload_checker.payload.manifest.install_operations, report,
-             'foo', 0, rootfs_part_size, 0, True, False)
+             'foo', 0, rootfs_part_size, 0, False)
     if should_fail:
       self.assertRaises(update_payload.PayloadError,
                         payload_checker._CheckOperations, *largs)
@@ -982,9 +991,11 @@
 
     # Generate payload (complete w/ signature) and create the test object.
     payload_checker = _GetPayloadChecker(
-        payload_gen.WriteToFileWithData, sigs_data=sigs_data,
-        privkey_file_name=_PRIVKEY_FILE_NAME,
-        do_add_pseudo_operation=(not do_forge_pseudo_op))
+        payload_gen.WriteToFileWithData,
+        payload_gen_dargs={
+            'sigs_data': sigs_data,
+            'privkey_file_name': _PRIVKEY_FILE_NAME,
+            'do_add_pseudo_operation': not do_forge_pseudo_op})
     payload_checker.payload_type = checker._TYPE_FULL
     report = checker._PayloadReport()
 
@@ -1004,7 +1015,7 @@
   def DoRunTest(self, fail_wrong_payload_type, fail_invalid_block_size,
                 fail_mismatched_block_size, fail_excess_data):
     # Generate a test payload. For this test, we generate a full update that
-    # has samle kernel and rootfs operations. Since most testing is done with
+    # has sample kernel and rootfs operations. Since most testing is done with
     # internal PayloadChecker methods that are tested elsewhere, here we only
     # tamper with what's actually being manipulated and/or tested in the Run()
     # method itself. Note that the checker doesn't verify partition hashes, so
@@ -1028,30 +1039,36 @@
         data_blob=os.urandom(kernel_part_size))
 
     # Generate payload (complete w/ signature) and create the test object.
-    payload_checker = _GetPayloadChecker(
-        payload_gen.WriteToFileWithData,
-        privkey_file_name=_PRIVKEY_FILE_NAME,
-        do_add_pseudo_operation=True, is_pseudo_in_kernel=True,
-        padding=os.urandom(1024) if fail_excess_data else None)
-
     if fail_invalid_block_size:
       use_block_size = block_size + 5  # not a power of two
     elif fail_mismatched_block_size:
       use_block_size = block_size * 2  # different that payload stated
     else:
       use_block_size = block_size
-    dargs = {
-        'pubkey_file_name': _PUBKEY_FILE_NAME,
-        'assert_type': 'delta' if fail_wrong_payload_type else 'full',
-        'block_size': use_block_size}
 
-    should_fail = (fail_wrong_payload_type or fail_invalid_block_size or
-                   fail_mismatched_block_size or fail_excess_data)
-    if should_fail:
-      self.assertRaises(update_payload.PayloadError,
-                        payload_checker.Run, **dargs)
+    dargs = {
+        'payload_gen_dargs': {
+            'privkey_file_name': _PRIVKEY_FILE_NAME,
+            'do_add_pseudo_operation': True,
+            'is_pseudo_in_kernel': True,
+            'padding': os.urandom(1024) if fail_excess_data else None},
+        'checker_init_dargs': {
+            'assert_type': 'delta' if fail_wrong_payload_type else 'full',
+            'block_size': use_block_size}}
+    if fail_invalid_block_size:
+      self.assertRaises(update_payload.PayloadError, _GetPayloadChecker,
+                        payload_gen.WriteToFileWithData, **dargs)
     else:
-      self.assertIsNone(payload_checker.Run(**dargs))
+      payload_checker = _GetPayloadChecker(payload_gen.WriteToFileWithData,
+                                           **dargs)
+      dargs = {'pubkey_file_name': _PUBKEY_FILE_NAME}
+      should_fail = (fail_wrong_payload_type or fail_mismatched_block_size or
+                     fail_excess_data)
+      if should_fail:
+        self.assertRaises(update_payload.PayloadError,
+                          payload_checker.Run, **dargs)
+      else:
+        self.assertIsNone(payload_checker.Run(**dargs))
 
 
 # This implements a generic API, hence the occasional unused args.
diff --git a/scripts/update_payload/payload.py b/scripts/update_payload/payload.py
index dbb385a..b4760b2 100644
--- a/scripts/update_payload/payload.py
+++ b/scripts/update_payload/payload.py
@@ -175,7 +175,7 @@
 
   def Check(self, pubkey_file_name=None, metadata_sig_file=None,
             report_out_file=None, assert_type=None, block_size=0,
-            allow_unhashed=False):
+            allow_unhashed=False, disabled_tests=()):
     """Checks the payload integrity.
 
     Args:
@@ -185,6 +185,7 @@
       assert_type: assert that payload is either 'full' or 'delta'
       block_size: expected filesystem / payload block size
       allow_unhashed: allow unhashed operation blobs
+      disabled_tests: list of tests to disable
     Raises:
       PayloadError if payload verification failed.
 
@@ -192,11 +193,12 @@
     self._AssertInit()
 
     # Create a short-lived payload checker object and run it.
-    helper = checker.PayloadChecker(self)
+    helper = checker.PayloadChecker(
+        self, assert_type=assert_type, block_size=block_size,
+        allow_unhashed=allow_unhashed, disabled_tests=disabled_tests)
     helper.Run(pubkey_file_name=pubkey_file_name,
                metadata_sig_file=metadata_sig_file,
-               report_out_file=report_out_file, assert_type=assert_type,
-               block_size=block_size, allow_unhashed=allow_unhashed)
+               report_out_file=report_out_file)
 
   def Apply(self, dst_kernel_part, dst_rootfs_part, src_kernel_part=None,
             src_rootfs_part=None):