Index: lnt/external/stats/pstat.py
===================================================================
--- lnt/external/stats/pstat.py
+++ lnt/external/stats/pstat.py
@@ -106,7 +106,6 @@
 ## 11/08/98 ... fixed aput to output large arrays correctly
 
 from __future__ import print_function
-import stats  # required 3rd party module
 import string, copy
 from types import *
 
Index: lnt/external/stats/stats.py
===================================================================
--- lnt/external/stats/stats.py
+++ lnt/external/stats/stats.py
@@ -223,7 +223,7 @@
 ##              fixed (a)histogram (which sometimes counted points <lowerlimit)
 
 from __future__ import print_function
-import pstat               # required 3rd party module
+from . import pstat               # required 3rd party module
 import math, string, copy  # required python modules
 from types import *
 
Index: lnt/formats/__init__.py
===================================================================
--- lnt/formats/__init__.py
+++ lnt/formats/__init__.py
@@ -7,12 +7,13 @@
 callable taking a Python object to write, and the path_or_file to write to.
 """
 
-from PlistFormat import format as plist
-from JSONFormat import format as json
+from typing import List, Dict
+from .PlistFormat import format as plist
+from .JSONFormat import format as json
 
-formats = [plist, json]
-formats_by_name = dict((f['name'], f) for f in formats)
-format_names = list(formats_by_name.keys())
+formats = [plist, json]  # type: List[Dict]
+formats_by_name = dict((f['name'], f) for f in formats)  # type: Dict[str, Dict]
+format_names = list(formats_by_name.keys())  # type: List[str]
 
 
 def get_format(name):
Index: lnt/lnttool/__init__.py
===================================================================
--- lnt/lnttool/__init__.py
+++ lnt/lnttool/__init__.py
@@ -1 +1 @@
-from main import main
+from .main import main
Index: lnt/server/db/testsuite.py
===================================================================
--- lnt/server/db/testsuite.py
+++ lnt/server/db/testsuite.py
@@ -4,13 +4,12 @@
 
 import json
 import lnt
-import testsuitedb
-import util
+from . import util
 
 import sqlalchemy
 import sqlalchemy.ext.declarative
 import sqlalchemy.orm
-from sqlalchemy import Column, Integer, ForeignKey, String, Binary
+from sqlalchemy import Column, Integer, ForeignKey, String, Binary, Float
 from sqlalchemy.orm import relation
 from lnt.util import logger
 
@@ -59,6 +58,35 @@
         return '%s%r' % (self.__class__.__name__, (self.name,))
 
 
+_sample_type_to_sql = {
+    'Real': Float,
+    'Hash': String,
+    'Status': Integer,
+}
+
+
+def is_known_sample_type(name):
+    return name in _sample_type_to_sql
+
+
+def make_sample_column(name, type):
+    sqltype = _sample_type_to_sql.get(type)
+    if sqltype is None:
+        raise ValueError("test suite defines unknown sample type %r" % type)
+    options = []
+    if type == 'Status':
+        options.append(ForeignKey(StatusKind.id))
+    return Column(name, sqltype, *options)
+
+
+def make_run_column(name):
+    return Column(name, String(256))
+
+
+def make_machine_column(name):
+    return Column(name, String(256))
+
+
 class _MigrationError(Exception):
     def __init__(self, message):
         full_message = \
@@ -149,7 +177,7 @@
             display_name = metric_desc.get('display_name')
             unit = metric_desc.get('unit')
             unit_abbrev = metric_desc.get('unit_abbrev')
-            if not testsuitedb.is_known_sample_type(metric_type_name):
+            if not is_known_sample_type(metric_type_name):
                 raise ValueError("Unknown metric type '%s'" %
                                  metric_type_name)
             metric_type = SampleType(metric_type_name)
@@ -369,7 +397,7 @@
                                       name)
         elif not dry_run:
             # Add missing columns
-            column = testsuitedb.make_sample_column(name, type)
+            column = make_sample_column(name, type)
             util.add_column(connectable, '%s_Sample' % ts_name, column)
 
     if len(old_metrics) != 0:
@@ -396,7 +424,7 @@
         old_field = old_run_fields.pop(name, None)
         # Add missing columns
         if old_field is None and not dry_run:
-            column = testsuitedb.make_run_column(name)
+            column = make_run_column(name)
             util.add_column(connectable, '%s_Run' % ts_name, column)
 
     if len(old_run_fields) > 0:
@@ -416,7 +444,7 @@
         old_field = old_machine_fields.pop(name, None)
         # Add missing columns
         if old_field is None and not dry_run:
-            column = testsuitedb.make_machine_column(name)
+            column = make_machine_column(name)
             util.add_column(connectable, '%s_Machine' % ts_name, column)
 
     if len(old_machine_fields) > 0:
Index: lnt/server/db/testsuitedb.py
===================================================================
--- lnt/server/db/testsuitedb.py
+++ lnt/server/db/testsuitedb.py
@@ -18,7 +18,7 @@
 from typing import List
 from lnt.util import logger
 
-import testsuite
+from . import testsuite
 import lnt.testing.profile.profile as profile
 import lnt
 from lnt.server.ui.util import convert_revision
@@ -32,35 +32,6 @@
         base_dict[key] = value
 
 
-_sample_type_to_sql = {
-    'Real': Float,
-    'Hash': String,
-    'Status': Integer,
-}
-
-
-def is_known_sample_type(name):
-    return name in _sample_type_to_sql
-
-
-def make_sample_column(name, type):
-    sqltype = _sample_type_to_sql.get(type)
-    if sqltype is None:
-        raise ValueError("test suite defines unknown sample type %r" % type)
-    options = []
-    if type == 'Status':
-        options.append(ForeignKey(testsuite.StatusKind.id))
-    return Column(name, sqltype, *options)
-
-
-def make_run_column(name):
-    return Column(name, String(256))
-
-
-def make_machine_column(name):
-    return Column(name, String(256))
-
-
 class MachineInfoChanged(ValueError):
     pass
 
@@ -152,7 +123,8 @@
                     raise ValueError("test suite defines reserved key %r" % (
                         iname))
 
-                class_dict[iname] = item.column = make_machine_column(iname)
+                item.column = testsuite.make_machine_column(iname)
+                class_dict[iname] = item.column
 
             def __init__(self, name_value):
                 self.id = None
@@ -355,7 +327,8 @@
                     raise ValueError("test suite defines reserved key %r" %
                                      (iname,))
 
-                class_dict[iname] = item.column = make_run_column(iname)
+                item.column = testsuite.make_run_column(iname)
+                class_dict[iname] = item.column
 
             def __init__(self, new_id, machine, order, start_time, end_time):
                 self.id = new_id
@@ -536,7 +509,8 @@
                     raise ValueError("test suite defines reserved key %r" %
                                      (iname,))
 
-                item.column = make_sample_column(iname, item.type.name)
+                item.column = testsuite.make_sample_column(iname,
+                                                           item.type.name)
                 class_dict[iname] = item.column
 
             def __init__(self, run, test, **kwargs):
Index: lnt/testing/profile/__init__.py
===================================================================
--- lnt/testing/profile/__init__.py
+++ lnt/testing/profile/__init__.py
@@ -1,7 +1,7 @@
 # This is the profile implementation registry. Register new profile
 # implementations here.
 
-from profilev1impl import ProfileV1
-from profilev2impl import ProfileV2
-from perf import LinuxPerfProfile
+from .profilev1impl import ProfileV1
+from .profilev2impl import ProfileV2
+from .perf import LinuxPerfProfile
 IMPLEMENTATIONS = {0: LinuxPerfProfile, 1: ProfileV1, 2: ProfileV2}
Index: lnt/testing/profile/perf.py
===================================================================
--- lnt/testing/profile/perf.py
+++ lnt/testing/profile/perf.py
@@ -1,6 +1,6 @@
 from lnt.util import logger
-from profile import ProfileImpl
-from profilev1impl import ProfileV1
+from .profile import ProfileImpl
+from .profilev1impl import ProfileV1
 
 import os
 import traceback
Index: lnt/testing/profile/profilev2impl.py
===================================================================
--- lnt/testing/profile/profilev2impl.py
+++ lnt/testing/profile/profilev2impl.py
@@ -1,4 +1,4 @@
-from profile import ProfileImpl
+from .profile import ProfileImpl
 import StringIO
 import bz2
 import copy
Index: lnt/tests/nt.py
===================================================================
--- lnt/tests/nt.py
+++ lnt/tests/nt.py
@@ -33,7 +33,7 @@
 from lnt.server.reporting.analysis import REGRESSED, IMPROVED
 from lnt.util import logger
 from lnt.lnttool.common import submit_options
-import builtintest
+from . import builtintest
 
 
 class TestModule(object):