diff --git a/frontend/afe/site_rpc_interface.py b/frontend/afe/site_rpc_interface.py
index 2cdeb73..a50763d 100644
--- a/frontend/afe/site_rpc_interface.py
+++ b/frontend/afe/site_rpc_interface.py
@@ -7,8 +7,8 @@
 import common
 import datetime
 import logging
-import sys
-from autotest_lib.client.common_lib import error, global_config
+
+from autotest_lib.client.common_lib import error
 from autotest_lib.client.common_lib.cros import dev_server
 from autotest_lib.server.cros.dynamic_suite import constants
 from autotest_lib.server.cros.dynamic_suite import control_file_getter
@@ -83,7 +83,8 @@
     @param pool: Specify the pool of machines to use for scheduling
             purposes.
     @param check_hosts: require appropriate live hosts to exist in the lab.
-    @param num: Specify the number of machines to schedule across.
+    @param num: Specify the number of machines to schedule across (integer).
+                Leave unspecified or use None to use default sharding factor.
     @param file_bugs: File a bug on each test failure in this suite.
 
     @raises ControlFileNotFound: if a unique suite control file doesn't exist.
@@ -96,16 +97,13 @@
     """
     # All suite names are assumed under test_suites/control.XX.
     suite_name = canonicalize_suite_name(suite_name)
-    try:
-        if num is None:  # Yes, specifically None
-            numeric_num = None
-        elif num == '0':
-            logging.warning("Can't run on 0 hosts; using default.")
-            numeric_num = None
-        else:
-            numeric_num = int(num)
-    except (ValueError, TypeError) as e:
-        raise error.SuiteArgumentException('Ill-specified num argument: %s' % e)
+
+    if type(num) is not int and num is not None:
+        raise error.SuiteArgumentException('Ill specified num argument. Must be'
+                                           ' an integer or None.')
+    if num == 0:
+        logging.warning("Can't run on 0 hosts; using default.")
+        num = None
 
     timings = {}
     # Ensure components of |build| necessary for installing images are staged
@@ -129,7 +127,7 @@
                    'build': build,
                    'check_hosts': check_hosts,
                    'pool': pool,
-                   'num': numeric_num,
+                   'num': num,
                    'file_bugs': file_bugs}
     control_file = tools.inject_vars(inject_dict, control_file_in)
 
diff --git a/frontend/afe/site_rpc_interface_unittest.py b/frontend/afe/site_rpc_interface_unittest.py
index 05d16c5..42b837f 100644
--- a/frontend/afe/site_rpc_interface_unittest.py
+++ b/frontend/afe/site_rpc_interface_unittest.py
@@ -56,11 +56,15 @@
             mox.IgnoreArg(), mox.IgnoreArg()).AndReturn(self.getter)
 
 
-    def _mockRpcUtils(self, to_return):
+    def _mockRpcUtils(self, to_return, control_file_substring=''):
         """Fake out the autotest rpc_utils module with a mockable class.
 
         @param to_return: the value that rpc_utils.create_job_common() should
                           be mocked out to return.
+        @param control_file_substring: A substring that is expected to appear
+                                       in the control file output string that
+                                       is passed to create_job_common.
+                                       Default: ''
         """
         download_started_time = constants.DOWNLOAD_STARTED_TIME
         payload_finished_time = constants.PAYLOAD_FINISHED_TIME
@@ -70,7 +74,9 @@
                             priority='Medium',
                             control_type='Server',
                             control_file=mox.And(mox.StrContains(self._BOARD),
-                                                 mox.StrContains(self._BUILD)),
+                                                 mox.StrContains(self._BUILD),
+                                                 mox.StrContains(
+                                                     control_file_substring)),
                             hostless=True,
                             keyvals=mox.And(mox.In(download_started_time),
                                             mox.In(payload_finished_time))
@@ -142,6 +148,14 @@
                           self._BUILD,
                           None,
                           num=[])
+        self.assertRaises(error.SuiteArgumentException,
+                          site_rpc_interface.create_suite_job,
+                          self._NAME,
+                          self._BOARD,
+                          self._BUILD,
+                          None,
+                          num='5')
+
 
 
     def testCreateSuiteJobFail(self):
@@ -187,9 +201,27 @@
         job_id = 5
         self._mockRpcUtils(job_id)
         self.mox.ReplayAll()
-        self.assertEquals(
-                site_rpc_interface.create_suite_job(
-                        self._NAME, self._BOARD, self._BUILD, None, False),
+        self.assertEquals(site_rpc_interface.create_suite_job(self._NAME,
+                                                              self._BOARD,
+                                                              self._BUILD,
+                                                              None, False),
+                job_id)
+
+    def testCreateSuiteIntegerNum(self):
+        """Ensures that success results in a successful RPC."""
+        self._mockDevServerGetter()
+        self.dev_server.trigger_download(self._BUILD,
+                                         synchronous=False).AndReturn(True)
+        self.getter.get_control_file_contents_by_name(
+            self._SUITE_NAME).AndReturn('f')
+        job_id = 5
+        self._mockRpcUtils(job_id, control_file_substring='num=17')
+        self.mox.ReplayAll()
+        self.assertEquals(site_rpc_interface.create_suite_job(self._NAME,
+                                                              self._BOARD,
+                                                              self._BUILD,
+                                                              None, False,
+                                                              num=17),
                 job_id)
 
 
diff --git a/site_utils/suite_scheduler/deduping_scheduler.py b/site_utils/suite_scheduler/deduping_scheduler.py
index 550c5dc..fd99196 100644
--- a/site_utils/suite_scheduler/deduping_scheduler.py
+++ b/site_utils/suite_scheduler/deduping_scheduler.py
@@ -4,7 +4,6 @@
 
 import logging
 from autotest_lib.server.cros.dynamic_suite import frontend_wrappers
-from autotest_lib.server import frontend
 
 
 class DedupingSchedulerException(Exception):
@@ -73,6 +72,7 @@
         @param pool: the pool of machines to use for scheduling purposes.
                      Default: None
         @param num: the number of devices across which to shard the test suite.
+                    Type: integer or None
                     Default: None (uses sharding factor in global_config.ini).
         @return True if the suite got scheduled
         @raise ScheduleException if an error occurs while scheduling.
@@ -107,6 +107,7 @@
                       x86-alex-release/R18-1655.0.0-a1-b1584.
         @param pool: the pool of machines to use for scheduling purposes.
         @param num: the number of devices across which to shard the test suite.
+                    Type: integer or None
         @param force: Always schedule the suite.
         @return True if the suite got scheduled, False if not
         @raise DedupException if we can't check for dups.
diff --git a/site_utils/suite_scheduler/task.py b/site_utils/suite_scheduler/task.py
index c53938a..4e32fed 100644
--- a/site_utils/suite_scheduler/task.py
+++ b/site_utils/suite_scheduler/task.py
@@ -4,7 +4,7 @@
 
 
 import logging, re
-import deduping_scheduler, forgiving_config_parser
+import deduping_scheduler
 from distutils import version
 from constants import Labels
 
@@ -136,13 +136,14 @@
         @param pool: the pool of machines to use for scheduling purposes.
                      Default: None
         @param num: the number of devices across which to shard the test suite.
+                    Type: integer or None
                     Default: None
         """
         self._name = name
         self._suite = suite
         self._branch_specs = branch_specs
         self._pool = pool
-        self._num = '%d' % num if num else None
+        self._num = num
 
         self._bare_branches = []
         if not branch_specs:
@@ -159,7 +160,7 @@
         # Since we expect __hash__() and other comparitor methods to be used
         # frequently by set operations, and they use str() a lot, pre-compute
         # the string representation of this object.
-        self._str = '%s: %s on %s with pool %s, across %r machines' % (
+        self._str = '%s: %s on %s with pool %s, across %d machines' % (
             self.__class__.__name__, suite, branch_specs, pool, num)