diff --git a/saqc/__init__.py b/saqc/__init__.py
index a801471cfe57053267271de325717b35e8a0233f..254c456229e09fd27a3458284413f44db45aebd5 100644
--- a/saqc/__init__.py
+++ b/saqc/__init__.py
@@ -7,8 +7,25 @@
 
 """The System for automated Quality Control package."""
 
+__all__ = [
+    "BAD",
+    "DOUBTFUL",
+    "GOOD",
+    "UNFLAGGED",
+    "FILTER_ALL",
+    "FILTER_NONE",
+    "Flags",
+    "DictOfSeries",
+    "SaQC",
+    "DmpScheme",
+    "FloatScheme",
+    "PositionalScheme",
+    "SimpleScheme",
+    "AnnotatedFloatScheme",
+    "fromConfig",
+]
+
 from saqc.constants import BAD, DOUBTFUL, FILTER_ALL, FILTER_NONE, GOOD, UNFLAGGED
-from saqc.exceptions import ParsingError
 from saqc.core import Flags, DictOfSeries, SaQC
 from saqc.core.translation import (
     DmpScheme,
@@ -18,8 +35,6 @@ from saqc.core.translation import (
     AnnotatedFloatScheme,
 )
 from saqc.parsing.reader import fromConfig
-from saqc.version import __version__
-
 from . import _version
 
 __version__ = _version.get_versions()["version"]
diff --git a/saqc/__main__.py b/saqc/__main__.py
index d5da0036369e3b1561e06b2cd38df59e4e5f9071..be2263500d6952caeeed48a3627b0fb3887ed28a 100644
--- a/saqc/__main__.py
+++ b/saqc/__main__.py
@@ -136,10 +136,10 @@ def main(
     config = str(config)
     cr = _ConfigReader(data=data, scheme=scheme)
     if config.endswith("json"):
-        f = None
-        if json_field is not None:
-            f = lambda j: j[str(json_field)]
-        cr = cr.readJson(config, unpack=f)
+        cr = cr.readJson(
+            config,
+            unpack=lambda j: j[str(json_field)] if json_field is not None else None,
+        )
     else:
         cr = cr.readCsv(config)
 
diff --git a/saqc/core/__init__.py b/saqc/core/__init__.py
index 1fbe7e27cf16682bce68df38479da20179647b19..bd5ac9dc696ce34eb69f3fe4427eb2caa5ef42aa 100644
--- a/saqc/core/__init__.py
+++ b/saqc/core/__init__.py
@@ -4,8 +4,19 @@
 # -*- coding: utf-8 -*-
 
 # isort: skip_file
+
+__all__ = [
+    "DictOfSeries",
+    "History",
+    "Flags",
+    "SaQC",
+    "flagging",
+    "processing",
+    "register",
+]
+
 from saqc.core.frame import DictOfSeries
 from saqc.core.history import History
-from saqc.core.flags import Flags, initFlagsLike
+from saqc.core.flags import Flags
 from saqc.core.register import flagging, processing, register
 from saqc.core.core import SaQC
diff --git a/saqc/core/core.py b/saqc/core/core.py
index c669da5672c4a2f8e4db344605bcb5fd5f24193c..952b2ed8cf9d6df9043b317bbb44c0f1c7adada5 100644
--- a/saqc/core/core.py
+++ b/saqc/core/core.py
@@ -12,7 +12,7 @@ import warnings
 from copy import copy as shallowcopy
 from copy import deepcopy
 from functools import partial
-from typing import Any, Hashable, Iterable, MutableMapping
+from typing import Any, Hashable, Iterable
 
 import numpy as np
 import pandas as pd
@@ -332,7 +332,7 @@ class SaQC(FunctionsMixin):
     def _castData(self, data) -> DictOfSeries:
         if isinstance(data, pd.Series):
             if not isinstance(data.name, str):
-                raise ValueError(f"Cannot init from unnamed pd.Series")
+                raise ValueError("Cannot init from unnamed pd.Series")
             data = data.to_frame()
         if isinstance(data, pd.DataFrame):
             for idx in [data.index, data.columns]:
diff --git a/saqc/core/flags.py b/saqc/core/flags.py
index e597e0ee184483abf593c815cd375897a29e0fe4..fc1684193a29c4c9add225392b0f1eb0fcdfae70 100644
--- a/saqc/core/flags.py
+++ b/saqc/core/flags.py
@@ -7,7 +7,6 @@
 from __future__ import annotations
 
 import typing
-import warnings
 from typing import DefaultDict, Dict, Iterable, Mapping, Tuple, Type, Union, overload
 
 import numpy as np
@@ -243,7 +242,7 @@ class Flags:
         if history.empty:
             return history
 
-        errm = f"History "
+        errm = "History "
         if colname:
             errm += f"of column {colname} "
 
diff --git a/saqc/core/translation/__init__.py b/saqc/core/translation/__init__.py
index 7549e43c599a7f838f710b03be734d8229707dda..1aaca2982f61bb95076a4c69caef890f9b889ecf 100644
--- a/saqc/core/translation/__init__.py
+++ b/saqc/core/translation/__init__.py
@@ -5,6 +5,16 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 # -*- coding: utf-8 -*-
+__all__ = [
+    "MappingScheme",
+    "TranslationScheme",
+    "DmpScheme",
+    "AnnotatedFloatScheme",
+    "FloatScheme",
+    "PositionalScheme",
+    "SimpleScheme",
+]
+
 from saqc.core.translation.basescheme import MappingScheme, TranslationScheme
 from saqc.core.translation.dmpscheme import DmpScheme
 from saqc.core.translation.floatscheme import AnnotatedFloatScheme, FloatScheme
diff --git a/saqc/core/translation/dmpscheme.py b/saqc/core/translation/dmpscheme.py
index fb68713d525520bda5369a497139fe8bb13d2a39..f80267c93ee2314e94edbb153666ad14dea1c973 100644
--- a/saqc/core/translation/dmpscheme.py
+++ b/saqc/core/translation/dmpscheme.py
@@ -9,7 +9,6 @@
 from __future__ import annotations
 
 import json
-from functools import reduce
 
 import numpy as np
 import pandas as pd
@@ -18,7 +17,6 @@ from saqc import BAD, DOUBTFUL, GOOD, UNFLAGGED
 from saqc.core import Flags, History
 from saqc.core.frame import DictOfSeries
 from saqc.core.translation.basescheme import BackwardMap, ForwardMap, MappingScheme
-from saqc.lib.tools import getUnionIndex
 
 _QUALITY_CAUSES = [
     "",
diff --git a/saqc/funcs/changepoints.py b/saqc/funcs/changepoints.py
index ff706f69167ec2e308057cf9eacfc3659d6141fd..b0ce725b3c0b1570c55c1f0ee8e7e8cb9a276f11 100644
--- a/saqc/funcs/changepoints.py
+++ b/saqc/funcs/changepoints.py
@@ -13,13 +13,11 @@ import numpy as np
 import pandas as pd
 
 from saqc import BAD, UNFLAGGED
-from saqc.core import DictOfSeries, Flags, flagging, register
+from saqc.core import flagging, register
 from saqc.lib.checking import (
-    isInBounds,
     validateCallable,
     validateChoice,
     validateMinPeriods,
-    validateValueBounds,
     validateWindow,
 )
 
diff --git a/saqc/funcs/flagtools.py b/saqc/funcs/flagtools.py
index d7ea5015a993c589355ae2c520a69ba4af2943fb..f57822e35fbc6e8a2ba44654677a22c3ff5202df 100644
--- a/saqc/funcs/flagtools.py
+++ b/saqc/funcs/flagtools.py
@@ -17,7 +17,6 @@ from typing_extensions import Literal
 
 from saqc import BAD, FILTER_ALL, UNFLAGGED
 from saqc.core import DictOfSeries, flagging, register
-from saqc.core.flags import Flags
 from saqc.core.history import History
 from saqc.lib.checking import validateChoice, validateWindow
 from saqc.lib.tools import (
@@ -446,7 +445,7 @@ class FlagtoolsMixin:
 
         fields, targets, broadcasting = multivariateParameters(field, target)
         meta = {
-            "func": f"transferFlags",
+            "func": "transferFlags",
             "args": (),
             "kwargs": {
                 "field": field,
diff --git a/saqc/funcs/generic.py b/saqc/funcs/generic.py
index ad8b200677ed7bd4b1f7a8b0bca9f7db1dc458ad..4973883dbd7e6b133b5bc32720d73357a852a5d0 100644
--- a/saqc/funcs/generic.py
+++ b/saqc/funcs/generic.py
@@ -267,7 +267,7 @@ class GenericMixin:
             )
 
         if not result.empty and not isAllBoolean(result):
-            raise TypeError(f"generic expression does not return a boolean array")
+            raise TypeError("generic expression does not return a boolean array")
 
         # update flags & data
         for i, col in enumerate(targets):
diff --git a/saqc/funcs/interpolation.py b/saqc/funcs/interpolation.py
index 481c87d725d55acad95ca63b91413453953fc31a..65501df34c92c5305bb8dbb8bd7e93bcb6f436ad 100644
--- a/saqc/funcs/interpolation.py
+++ b/saqc/funcs/interpolation.py
@@ -7,7 +7,6 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
-import warnings
 from typing import TYPE_CHECKING, Callable, Tuple, Union
 
 import numpy as np
@@ -18,8 +17,6 @@ from saqc import UNFLAGGED
 from saqc.core import register
 from saqc.core.history import History
 from saqc.lib.checking import (
-    isValidChoice,
-    validateCallable,
     validateChoice,
     validateFuncSelection,
     validateMinPeriods,
diff --git a/saqc/funcs/noise.py b/saqc/funcs/noise.py
index 7e18add8f6477fb6e57f4f3614331a402ead144d..db60bf214414db739b4180896606d2dbe8ddad60 100644
--- a/saqc/funcs/noise.py
+++ b/saqc/funcs/noise.py
@@ -13,16 +13,10 @@ from typing import TYPE_CHECKING, Callable, Literal
 
 import numpy as np
 import pandas as pd
-from scipy.stats import median_abs_deviation
 
 from saqc.constants import BAD
 from saqc.core.register import flagging
-from saqc.lib.checking import (
-    isCallable,
-    validateFuncSelection,
-    validateMinPeriods,
-    validateWindow,
-)
+from saqc.lib.checking import validateFuncSelection, validateMinPeriods, validateWindow
 from saqc.lib.tools import isunflagged, statPass
 from saqc.parsing.environ import ENV_OPERATORS
 
diff --git a/saqc/funcs/outliers.py b/saqc/funcs/outliers.py
index 5ea2e2ddaebd91074d58b427a05b762538825ef8..ab878240208b6880260dd8baa8227d18e022b1a0 100644
--- a/saqc/funcs/outliers.py
+++ b/saqc/funcs/outliers.py
@@ -10,7 +10,7 @@ from __future__ import annotations
 
 import uuid
 import warnings
-from typing import TYPE_CHECKING, Callable, List, Optional, Sequence, Tuple
+from typing import TYPE_CHECKING, Callable, Sequence, Tuple
 
 import numpy as np
 import numpy.polynomial.polynomial as poly
@@ -27,7 +27,6 @@ from saqc.lib.checking import (
     validateChoice,
     validateFraction,
     validateFrequency,
-    validateFuncSelection,
     validateMinPeriods,
     validateValueBounds,
     validateWindow,
diff --git a/saqc/funcs/resampling.py b/saqc/funcs/resampling.py
index 168d16fc0f41b803c281974e2b9d26b38185cb2d..fb803e26c9875a703e443da4e3b0d267061e12a4 100644
--- a/saqc/funcs/resampling.py
+++ b/saqc/funcs/resampling.py
@@ -7,11 +7,10 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
-import re
 import typing
 import uuid
 import warnings
-from typing import TYPE_CHECKING, Callable, Union
+from typing import TYPE_CHECKING, Callable
 
 import numpy as np
 import pandas as pd
@@ -21,10 +20,9 @@ import saqc.constants
 from saqc.constants import UNFLAGGED
 from saqc.core import register
 from saqc.core.history import History
-from saqc.funcs.interpolation import DATA_REINDEXER
 from saqc.lib.checking import validateChoice, validateFuncSelection
 from saqc.lib.docs import DOC_TEMPLATES
-from saqc.lib.tools import filterKwargs, getFreqDelta
+from saqc.lib.tools import getFreqDelta
 from saqc.lib.ts_operators import isValid
 
 if TYPE_CHECKING:
@@ -288,10 +286,10 @@ class ResamplingMixin:
                 done = True
 
         if len(stack) == 0:
-            raise ValueError(f"Could not find no last reindexing to invert")
+            raise ValueError("Could not find no last reindexing to invert")
 
         reindex_method = METHODINVERTS.get(stack[-1], False)
-        if reindex_method == False:
+        if reindex_method is False:
             raise ValueError(f"cant invert {stack[-1]}")
         return reindex_method
 
diff --git a/saqc/funcs/residuals.py b/saqc/funcs/residuals.py
index 5ef4a6a409168bb8b05cee3075921de0f1c48ee5..0ba870798135b93a385e7e04510956532c9bd732 100644
--- a/saqc/funcs/residuals.py
+++ b/saqc/funcs/residuals.py
@@ -7,7 +7,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Optional, Union
+from typing import TYPE_CHECKING, Callable
 
 import numpy as np
 import pandas as pd
diff --git a/saqc/funcs/rolling.py b/saqc/funcs/rolling.py
index dfcdfd23cd747f59b6ccece0a89ffd2e847d2fd3..77a9d9985c458bdae31109be4a978e241b2bb193 100644
--- a/saqc/funcs/rolling.py
+++ b/saqc/funcs/rolling.py
@@ -14,12 +14,7 @@ import pandas as pd
 
 import saqc
 from saqc.core import DictOfSeries, Flags, register
-from saqc.lib.checking import (
-    validateCallable,
-    validateFuncSelection,
-    validateMinPeriods,
-    validateWindow,
-)
+from saqc.lib.checking import validateFuncSelection, validateMinPeriods, validateWindow
 from saqc.lib.tools import getFreqDelta
 
 if TYPE_CHECKING:
diff --git a/saqc/funcs/scores.py b/saqc/funcs/scores.py
index f72e2362f822d4d65d49f6d7332e5d83dd2cb483..aacc76eb33399decb0bee9869893ee94ca8c893e 100644
--- a/saqc/funcs/scores.py
+++ b/saqc/funcs/scores.py
@@ -7,14 +7,13 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Optional, Sequence, Tuple, Union
+from typing import TYPE_CHECKING, Callable, Optional, Sequence, Tuple
 
 import numpy as np
 import pandas as pd
 from sklearn.neighbors import LocalOutlierFactor
 from typing_extensions import Literal
 
-from saqc import UNFLAGGED
 from saqc.core import register
 from saqc.lib.checking import (
     validateChoice,
@@ -25,7 +24,7 @@ from saqc.lib.checking import (
 from saqc.lib.docs import DOC_TEMPLATES
 from saqc.lib.tools import getApply, toSequence
 from saqc.lib.ts_operators import kNN
-from saqc.parsing.environ import ENV_OPERATORS, ENV_TRAFOS
+from saqc.parsing.environ import ENV_OPERATORS
 
 if TYPE_CHECKING:
     from saqc import SaQC
diff --git a/saqc/funcs/tools.py b/saqc/funcs/tools.py
index 453d28d882350363bbae52dece9085d981f82f08..5038df6294c09868959cb61b18c0a9a3061b4c0b 100644
--- a/saqc/funcs/tools.py
+++ b/saqc/funcs/tools.py
@@ -9,7 +9,6 @@ from __future__ import annotations
 
 import pickle
 import tkinter as tk
-import warnings
 from typing import TYPE_CHECKING
 
 import matplotlib as mpl
diff --git a/saqc/funcs/transformation.py b/saqc/funcs/transformation.py
index 2b2d6db440895a949939068acb7395abd6d1786a..cfc4d226aaf6d5d95181ef2a0dc4149a076e087d 100644
--- a/saqc/funcs/transformation.py
+++ b/saqc/funcs/transformation.py
@@ -7,7 +7,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Optional, Union
+from typing import TYPE_CHECKING, Callable
 
 import numpy as np
 import pandas as pd
diff --git a/saqc/lib/plotting.py b/saqc/lib/plotting.py
index 5dd0e944b93d93e1e0b15ddd723bb88d0b4fd5e3..41a5b5a53f0a1df379c396bd8fa11309c30a5c7b 100644
--- a/saqc/lib/plotting.py
+++ b/saqc/lib/plotting.py
@@ -9,7 +9,6 @@
 from __future__ import annotations
 
 import itertools
-from collections import OrderedDict
 
 import matplotlib as mpl
 import matplotlib.pyplot as plt
diff --git a/saqc/lib/tools.py b/saqc/lib/tools.py
index 72c201c8f36a6afa1393edfe0082472eccd1b6cd..7fd671036660d222aa59dba05b6197a212f9285d 100644
--- a/saqc/lib/tools.py
+++ b/saqc/lib/tools.py
@@ -442,7 +442,7 @@ def getApply(in_obj, apply_obj, attr_access="__name__", attr_or="apply") -> pd.S
         try:
             # let's try to run it somewhat optimized
             out = getattr(in_obj, attr_or)(apply_obj, raw=True)
-        except:
+        except Exception:
             # did't work out, fallback
             out = getattr(in_obj, attr_or)(apply_obj)
 
diff --git a/saqc/lib/ts_operators.py b/saqc/lib/ts_operators.py
index c983a314f87bd2bf373fdc8dc7b821b2ea1bf6b9..4b0c4ad44f4b77d34a4f10d9c812bd99a3eb5e9e 100644
--- a/saqc/lib/ts_operators.py
+++ b/saqc/lib/ts_operators.py
@@ -9,10 +9,7 @@
 """
 The module gathers all kinds of timeseries tranformations.
 """
-import re
 import sys
-import warnings
-from typing import Literal, Union
 
 import numpy as np
 import numpy.polynomial.polynomial as poly
diff --git a/saqc/lib/types.py b/saqc/lib/types.py
index 8b5b6e5fa77b1e1c0f443f9bc50abdb694362808..c5e784527dc43769731cec124753110be62d7f51 100644
--- a/saqc/lib/types.py
+++ b/saqc/lib/types.py
@@ -8,20 +8,12 @@
 from __future__ import annotations
 
 import abc
-from typing import Any, Dict, TypeVar, Union
+from typing import TypeVar, Union
 
 import numpy as np
 import pandas as pd
 from typing_extensions import Protocol
 
-__all__ = [
-    "T",
-    "ArrayLike",
-    "CurveFitter",
-    "ExternalFlag",
-    "OptionalNone",
-]
-
 T = TypeVar("T")
 ArrayLike = TypeVar("ArrayLike", np.ndarray, pd.Series, pd.DataFrame)
 
diff --git a/saqc/parsing/environ.py b/saqc/parsing/environ.py
index a3095b36385703cea57e300a16b69be3e03c0dc1..d494ed666108df125ee93be3a04255c6c589e0ce 100644
--- a/saqc/parsing/environ.py
+++ b/saqc/parsing/environ.py
@@ -7,8 +7,6 @@
 # -*- coding: utf-8 -*-
 
 import numpy as np
-import pandas as pd
-import scipy.stats as st
 
 import saqc.lib.ts_operators as ts_ops
 from saqc import BAD, DOUBTFUL, FILTER_ALL, FILTER_NONE, GOOD, UNFLAGGED
diff --git a/tests/core/test_core.py b/tests/core/test_core.py
index 4109eb6e4a633786752c0b5272088b69751f9d3d..b5062f33f86e7466c4877d5d98f2ed7d18aafcb2 100644
--- a/tests/core/test_core.py
+++ b/tests/core/test_core.py
@@ -13,7 +13,8 @@ import pandas as pd
 import pytest
 
 from saqc import BAD, FILTER_ALL, FILTER_NONE, UNFLAGGED, SaQC
-from saqc.core import DictOfSeries, Flags, flagging, initFlagsLike, processing, register
+from saqc.core import DictOfSeries, Flags, flagging, processing, register
+from saqc.core.flags import initFlagsLike
 from saqc.lib.types import OptionalNone
 from tests.common import initData
 
diff --git a/tests/funcs/test_constants_detection.py b/tests/funcs/test_constants_detection.py
index 8cbf3290d58b2b76f80c8255aa874533b669a3cd..a6ec797929f933e413e4c7aa9c6478259914147a 100644
--- a/tests/funcs/test_constants_detection.py
+++ b/tests/funcs/test_constants_detection.py
@@ -9,8 +9,8 @@
 import numpy as np
 import pytest
 
-from saqc import BAD, UNFLAGGED
-from saqc.core import SaQC, initFlagsLike
+from saqc import BAD, UNFLAGGED, SaQC
+from saqc.core.flags import initFlagsLike
 from tests.common import initData
 
 
diff --git a/tests/funcs/test_functions.py b/tests/funcs/test_functions.py
index d956e39b1a1fb6532b328bd93672966c8cc41c55..8a3e14a53d4e57a04672a6c3fc93f7358d04e01b 100644
--- a/tests/funcs/test_functions.py
+++ b/tests/funcs/test_functions.py
@@ -10,9 +10,8 @@ import numpy as np
 import pandas as pd
 import pytest
 
-import saqc
-from saqc import BAD, DOUBTFUL, UNFLAGGED, SaQC
-from saqc.core import DictOfSeries, initFlagsLike
+from saqc import BAD, DOUBTFUL, UNFLAGGED, DictOfSeries, SaQC
+from saqc.core.flags import initFlagsLike
 from tests.common import initData
 from tests.fixtures import char_dict, course_1  # noqa, todo: fix fixtures
 
diff --git a/tests/funcs/test_generic_config_functions.py b/tests/funcs/test_generic_config_functions.py
index f19342a39a2d71421564d076c938d4197644cba0..d9af808da9f91e2387c5332e136aa1f1b1b0caca 100644
--- a/tests/funcs/test_generic_config_functions.py
+++ b/tests/funcs/test_generic_config_functions.py
@@ -12,8 +12,9 @@ import numpy as np
 import pandas as pd
 import pytest
 
-from saqc import BAD, UNFLAGGED, SaQC
-from saqc.core import DictOfSeries, Flags, initFlagsLike, register
+from saqc import BAD, UNFLAGGED, DictOfSeries, Flags, SaQC
+from saqc.core import register
+from saqc.core.flags import initFlagsLike
 from saqc.funcs.generic import _execGeneric
 from saqc.parsing.reader import _ConfigReader
 from saqc.parsing.visitor import ConfigFunctionParser
diff --git a/tests/funcs/test_outlier_detection.py b/tests/funcs/test_outlier_detection.py
index 81bd0ec287834f7d28a0bd85834064bc165c3c5b..61953bcd09e12826ecbce8db56257905c05938a5 100644
--- a/tests/funcs/test_outlier_detection.py
+++ b/tests/funcs/test_outlier_detection.py
@@ -13,8 +13,8 @@ import pandas as pd
 import pytest
 
 import saqc
-from saqc import BAD, UNFLAGGED
-from saqc.core import DictOfSeries, SaQC, initFlagsLike
+from saqc import BAD, UNFLAGGED, DictOfSeries, SaQC
+from saqc.core.flags import initFlagsLike
 from tests.fixtures import char_dict, course_1, course_2, course_3, course_4
 
 
diff --git a/tests/funcs/test_pattern_rec.py b/tests/funcs/test_pattern_rec.py
index 6b96ee0ca5b6a44a962322eb98d7ffb54fdbf20f..b2be3a6348c017ab3a789c59d0d53b914bd77867 100644
--- a/tests/funcs/test_pattern_rec.py
+++ b/tests/funcs/test_pattern_rec.py
@@ -9,8 +9,8 @@
 import pandas as pd
 import pytest
 
-from saqc import BAD, UNFLAGGED, SaQC
-from saqc.core import DictOfSeries, initFlagsLike
+from saqc import BAD, UNFLAGGED, DictOfSeries, SaQC
+from saqc.core.flags import initFlagsLike
 from tests.common import initData
 
 
diff --git a/tests/funcs/test_proc_functions.py b/tests/funcs/test_proc_functions.py
index df960969b062e7a76e2a53e938f0200843d62ebf..b2f097060d982c31e516af49925d21467f9745fa 100644
--- a/tests/funcs/test_proc_functions.py
+++ b/tests/funcs/test_proc_functions.py
@@ -14,8 +14,8 @@ import pandas as pd
 import pytest
 
 import saqc
-from saqc import UNFLAGGED, SaQC
-from saqc.core import DictOfSeries, initFlagsLike
+from saqc import UNFLAGGED, DictOfSeries, SaQC
+from saqc.core.flags import initFlagsLike
 from saqc.lib.ts_operators import linearInterpolation, polynomialInterpolation
 from tests.fixtures import char_dict, course_3, course_5  # noqa, todo: fix fixtures
 
diff --git a/tests/funcs/test_resampling.py b/tests/funcs/test_resampling.py
index b765c074f64f44dfe2ee48ed85021a1b791d59be..f077c283b7314b89826dcc37bf79fe0ede3d18c8 100644
--- a/tests/funcs/test_resampling.py
+++ b/tests/funcs/test_resampling.py
@@ -14,7 +14,7 @@ import pandas as pd
 import pytest
 
 from saqc import SaQC
-from saqc.core import initFlagsLike
+from saqc.core.flags import initFlagsLike
 from saqc.funcs.resampling import (
     _aggregationGrouper,
     _constructAggregationReindexer,
diff --git a/tests/fuzzy/lib.py b/tests/fuzzy/lib.py
index a70a159f3ad1fede24e2c295ce74d6a672a8ffb4..e0b30cac99acce5eb77dd068d4bb956511290f67 100644
--- a/tests/fuzzy/lib.py
+++ b/tests/fuzzy/lib.py
@@ -23,8 +23,8 @@ from hypothesis.strategies import (
 )
 from hypothesis.strategies._internal.types import _global_type_lookup
 
-from saqc import BAD
-from saqc.core import DictOfSeries, initFlagsLike
+from saqc import BAD, DictOfSeries
+from saqc.core.flags import initFlagsLike
 from saqc.core.register import FUNC_MAP
 
 MAX_EXAMPLES = 50