diff --git a/my/core/cfg.py b/my/core/cfg.py
index d69f356..3321a4c 100644
--- a/my/core/cfg.py
+++ b/my/core/cfg.py
@@ -28,7 +28,7 @@ F = TypeVar('F')
 from contextlib import contextmanager
 from typing import Iterator
 @contextmanager
-def override_config(config: F) -> Iterator[F]:
+def _override_config(config: F) -> Iterator[F]:
     '''
     Temporary override for config's parameters, useful for testing/fake data/etc.
     '''
@@ -82,7 +82,7 @@ def tmp_config(*, modules: Optional[ModuleRegex]=None, config=None):
         assert config is not None
 
     import my.config
-    with ExitStack() as module_reload_stack, override_config(my.config) as new_config:
+    with ExitStack() as module_reload_stack, _override_config(my.config) as new_config:
         if config is not None:
             overrides = {k: v for k, v in vars(config).items() if not k.startswith('__')}
             for k, v in overrides.items():
@@ -104,3 +104,8 @@ def test_tmp_config() -> None:
     # todo hmm. not sure what should do about new properties??
     assert not hasattr(c, 'extra')
     assert c.google != 'whatever'
+
+
+###
+# todo properly deprecate, this isn't really meant for public use
+override_config = _override_config
diff --git a/my/core/core_config.py b/my/core/core_config.py
index 48f3eb4..f87a1ba 100644
--- a/my/core/core_config.py
+++ b/my/core/core_config.py
@@ -123,8 +123,8 @@ from contextlib import contextmanager as ctx
 @ctx
 def _reset_config() -> Iterator[Config]:
     # todo maybe have this decorator for the whole of my.config?
-    from .cfg import override_config
-    with override_config(config) as cc:
+    from .cfg import _override_config
+    with _override_config(config) as cc:
         cc.enabled_modules  = None
         cc.disabled_modules = None
         cc.cache_dir        = None
diff --git a/my/emfit/__init__.py b/my/emfit/__init__.py
index 997ba6c..a081416 100644
--- a/my/emfit/__init__.py
+++ b/my/emfit/__init__.py
@@ -3,6 +3,11 @@
 
 Consumes data exported by https://github.com/karlicoss/emfitexport
 """
+
+REQUIRES = [
+    'git+https://github.com/karlicoss/emfitexport',
+]
+
 from pathlib import Path
 from typing import Dict, List, Iterable, Any, Optional
 
@@ -140,16 +145,20 @@ def stats() -> Stats:
 from contextlib import contextmanager
 from typing import Iterator
 @contextmanager
-def fake_data(nights: int=500) -> Iterator[None]:
-    from ..core.cfg import override_config
+def fake_data(nights: int=500) -> Iterator:
+    from my.core.cfg import tmp_config
     from tempfile import TemporaryDirectory
-    with override_config(config) as cfg, TemporaryDirectory() as td:
+    with TemporaryDirectory() as td:
         tdir = Path(td)
-        cfg.export_path = tdir
-
         gen = dal.FakeData()
         gen.fill(tdir, count=nights)
-        yield
+
+        class override:
+            class emfit:
+                export_path = tdir
+
+        with tmp_config(modules=__name__, config=override) as cfg:
+            yield cfg
 
 
 # TODO remove/deprecate it? I think used by timeline
diff --git a/my/endomondo.py b/my/endomondo.py
index 0df7aa9..0fa396f 100644
--- a/my/endomondo.py
+++ b/my/endomondo.py
@@ -87,20 +87,24 @@ def stats() -> Stats:
 # TODO make sure it's possible to 'advise' functions and override stuff
 
 from contextlib import contextmanager
+from typing import Iterator
 @contextmanager
-def fake_data(count: int=100):
-    from .core.cfg import override_config
+def fake_data(count: int=100) -> Iterator:
+    from my.core.cfg import tmp_config
     from tempfile import TemporaryDirectory
     import json
-    with override_config(endomondo) as cfg, TemporaryDirectory() as td:
+    with TemporaryDirectory() as td:
         tdir = Path(td)
-        cfg.export_path = tdir
-
-        # todo would be nice to somehow expose the generator so it's possible to hack from the outside?
         fd = dal.FakeData()
         data = fd.generate(count=count)
 
         jf = tdir / 'data.json'
         jf.write_text(json.dumps(data))
 
-        yield
+        class override:
+            class endomondo:
+                export_path = tdir
+
+        with tmp_config(modules=__name__, config=override) as cfg:
+            # todo would be nice to somehow expose the generator so it's possible to hack from the outside?
+            yield cfg
diff --git a/my/rescuetime.py b/my/rescuetime.py
index 5d64375..40aa6b7 100644
--- a/my/rescuetime.py
+++ b/my/rescuetime.py
@@ -58,22 +58,27 @@ def stats() -> Stats:
 
 # basically, hack config and populate it with fake data? fake data generated by DAL, but the rest is handled by this?
 
-from typing import Iterator
 from contextlib import contextmanager
+from typing import Iterator
 # todo take seed, or what?
 @contextmanager
-def fake_data(rows: int=1000) -> Iterator[None]:
+def fake_data(rows: int=1000) -> Iterator:
     # todo also disable cachew automatically for such things?
-    from .core.cachew import disabled_cachew
-    from .core.cfg import override_config
+    from my.core.cfg import tmp_config
+    from my.core.cachew import disabled_cachew
     from tempfile import TemporaryDirectory
-    with disabled_cachew(), override_config(config) as cfg, TemporaryDirectory() as td:
+    import json
+    with disabled_cachew(), TemporaryDirectory() as td:
         tdir = Path(td)
-        cfg.export_path = tdir
         f = tdir / 'rescuetime.json'
-        import json
         f.write_text(json.dumps(dal.fake_data_generator(rows=rows)))
-        yield
+
+        class override:
+            class rescuetime:
+                export_path = tdir
+
+        with tmp_config(modules=__name__, config=override) as cfg:
+            yield cfg
 # TODO ok, now it's something that actually could run on CI!
 # todo would be kinda nice if doctor could run against the fake data, to have a basic health check of the module?