diff --git a/test/log_test.py b/test/log_test.py
new file mode 100755
index 0000000..6eca6aa
--- /dev/null
+++ b/test/log_test.py
@@ -0,0 +1,160 @@
+#!/usr/bin/env python3
+
+# osmo_gsm_tester: logging tests
+#
+# Copyright (C) 2016-2017 by sysmocom - s.f.m.c. GmbH
+#
+# Author: Neels Hofmeyr <neels@hofmeyr.de>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import _prep
+
+import sys
+import os
+
+from osmo_gsm_tester import log
+
+#log.targets[0].get_time_str = lambda: '01:02:03'
+fake_time = '01:02:03'
+log.style_change(time=True, time_fmt=fake_time)
+
+print('- Testing global log functions')
+log.log('<origin>', log.C_TST, 'from log.log()')
+log.dbg('<origin>', log.C_TST, 'from log.dbg(), not seen')
+log.set_level(log.C_TST, log.L_DBG)
+log.dbg('<origin>', log.C_TST, 'from log.dbg()')
+log.set_level(log.C_TST, log.L_LOG)
+log.err('<origin>', log.C_TST, 'from log.err()')
+
+print('- Testing log.Origin functions')
+class LogTest(log.Origin):
+    pass
+
+t = LogTest()
+t.set_log_category(log.C_TST)
+t.set_name('some', 'name', some="detail")
+	
+t.log("hello log")
+t.err("hello err")
+t.dbg("hello dbg not visible")
+
+t.log("message", int=3, tuple=('foo', 42), none=None, str='str\n')
+
+log.set_level(log.C_TST, log.L_DBG)
+t.dbg("hello dbg")
+
+print('- Testing log.style()')
+
+log.style(time=True, category=False, level=False, origin=False, src=False, time_fmt=fake_time)
+t.dbg("only time")
+log.style(time=False, category=True, level=False, origin=False, src=False, time_fmt=fake_time)
+t.dbg("only category")
+log.style(time=False, category=False, level=True, origin=False, src=False, time_fmt=fake_time)
+t.dbg("only level")
+log.style(time=False, category=False, level=False, origin=True, src=False, time_fmt=fake_time)
+t.dbg("only origin")
+log.style(time=False, category=False, level=False, origin=False, src=True, time_fmt=fake_time)
+t.dbg("only src")
+
+print('- Testing log.style_change()')
+log.style(time=False, category=False, level=False, origin=False, src=False, time_fmt=fake_time)
+t.dbg("no log format")
+log.style_change(time=True)
+t.dbg("add time")
+log.style_change(time=True, time_fmt=0)
+t.dbg("but no time format")
+log.style_change(time=True, time_fmt=fake_time)
+log.style_change(level=True)
+t.dbg("add level")
+log.style_change(category=True)
+t.dbg("add category")
+log.style_change(src=True)
+t.dbg("add src")
+log.style_change(origin=True)
+t.dbg("add origin")
+
+print('- Testing origin_width')
+t = LogTest()
+t.set_log_category(log.C_TST)
+t.set_name('shortname')
+log.style(origin_width=23, time_fmt=fake_time)
+t.log("origin str set to 23 chars")
+t.set_name('very long name', some='details', and_some=(3, 'things', 'in a tuple'))
+t.log("long origin str")
+t.dbg("long origin str dbg")
+t.err("long origin str err")
+
+print('- Testing log.Origin with omitted info')
+t = LogTest()
+t.set_log_category(log.C_TST)
+t.log("hello log, name implicit from class name")
+
+t = LogTest()
+t.set_name('explicit_name')
+t.log("hello log, no category set")
+
+t = LogTest()
+t.log("hello log, no category nor name set")
+t.dbg("hello log, no category nor name set, not seen")
+log.set_level(log.C_DEFAULT, log.L_DBG)
+t.dbg("debug message, no category nor name set")
+
+print('- Testing logging of Exceptions, tracing origins')
+log.style(time_fmt=fake_time)
+
+class Thing(log.Origin):
+    def __init__(self, some_path):
+        self.set_log_category(log.C_TST)
+        self.set_name(some_path)
+
+    def say(self, msg):
+        print(msg)
+
+#log.style_change(trace=True)
+
+with Thing('print_redirected'):
+    print("Not throwing an exception in 'with:' works.")
+
+def l1():
+    level1 = Thing('level1')
+    with level1:
+        l2()
+
+def l2():
+    level2 = Thing('level2')
+    with level2:
+        l3(level2)
+
+def l3(level2):
+    level3 = Thing('level3')
+    with level3:
+        print('nested print just prints')
+        level3.log('nested log()')
+        level2.log('nested l2 log() from within l3 scope')
+        raise ValueError('bork')
+
+try:
+    l1()
+except Exception:
+    log.log_exn()
+
+print('- Enter the same Origin context twice')
+with Thing('level1'):
+    l2 = Thing('level2')
+    with l2:
+        with l2:
+            l2.log('nested log')
+
+# vim: expandtab tabstop=4 shiftwidth=4