diff --git a/geomagio/algorithm/SqDistAlgorithm.py b/geomagio/algorithm/SqDistAlgorithm.py
index 4dc5087a230367e817f1dacaa4991d7523455d20..e2106c0fa1b83f92307b10f47ed3b311adca3ea8 100644
--- a/geomagio/algorithm/SqDistAlgorithm.py
+++ b/geomagio/algorithm/SqDistAlgorithm.py
@@ -461,7 +461,7 @@ class SqDistAlgorithm(Algorithm):
         # to White et al. (USGS SIR 2014-5045).
         fom = 10 ** (-3 / 20.0)  # halve power at corner frequency
         omg = np.pi / np.float64(smooth)  # corner angular frequency
-        sig = np.sqrt(-2 * np.log(fom) / omg ** 2) + np.finfo(float).eps  # sig>0
+        sig = np.sqrt(-2 * np.log(fom) / omg**2) + np.finfo(float).eps  # sig>0
         ts = np.linspace(
             np.max((-m, -3 * np.round(sig))),
             np.min((m, 3 * np.round(sig))),
@@ -536,7 +536,7 @@ class SqDistAlgorithm(Algorithm):
                     # when forecasting, grow sigma=sqrt(var) like a prediction
                     # interval; sumc2 and jstep will be reset with the next
                     # valid observation
-                    phiJminus1 = phiJminus1 + phi ** jstep
+                    phiJminus1 = phiJminus1 + phi**jstep
                     jstep = jstep + 1
                     sumc2 = (
                         sumc2
diff --git a/geomagio/geomag_types.py b/geomagio/geomag_types.py
index a50e2804e5baf21454dbdaf22f75254c51bd70ff..9a181bcd29aeb60fd1aa8e9ee52167ea0dedf602 100644
--- a/geomagio/geomag_types.py
+++ b/geomagio/geomag_types.py
@@ -1,4 +1,4 @@
-from typing_extensions import Literal
+from typing import Literal
 
 DataInterval = Literal["tenhertz", "second", "minute", "hour", "day", "month"]
 DataType = Literal[
diff --git a/geomagio/residual/Calculation.py b/geomagio/residual/Calculation.py
index fe1ab1c1ed48706ddb343a0282daec9842c69fe7..d6d820446db64c3526662cd4dff1f4be35a7653b 100644
--- a/geomagio/residual/Calculation.py
+++ b/geomagio/residual/Calculation.py
@@ -1,5 +1,4 @@
-from typing import List, Tuple
-from typing_extensions import Literal
+from typing import List, Literal, Tuple
 
 import numpy as np
 
@@ -116,7 +115,7 @@ def calculate_D_absolute(
             m.angle
             + np.degrees(
                 m.measurement_type.meridian
-                * (np.arcsin(m.residual / np.sqrt((m.h + h_baseline) ** 2 + m.e ** 2)))
+                * (np.arcsin(m.residual / np.sqrt((m.h + h_baseline) ** 2 + m.e**2)))
             )
             - np.degrees(np.arctan(m.e / (m.h + h_baseline)))
             for m in declination_measurements
@@ -168,7 +167,7 @@ def calculate_HZ_absolutes(
     inclination_radians = np.radians(inclination)
     h_abs = corrected_f * np.cos(inclination_radians)
     z_abs = corrected_f * np.sin(inclination_radians)
-    h_b = np.sqrt(h_abs ** 2 - mean.e ** 2) - mean.h
+    h_b = np.sqrt(h_abs**2 - mean.e**2) - mean.h
     z_b = z_abs - mean.z
     # adjust absolutes to reference measurement
     if reference:
diff --git a/geomagio/residual/Reading.py b/geomagio/residual/Reading.py
index 437da4992fd3bac827861ff3340c3743b530c143..101ba4b4b7ed3c7e36024e6c8234b03cb1aea55c 100644
--- a/geomagio/residual/Reading.py
+++ b/geomagio/residual/Reading.py
@@ -1,5 +1,4 @@
-from typing import Dict, List, Optional, Tuple
-from typing_extensions import Literal
+from typing import Dict, List, Literal, Optional, Tuple
 
 import numpy as np
 from obspy import Stream, UTCDateTime
@@ -187,7 +186,7 @@ def get_ordinates(
     d_ord = d_abs - d_bas
     z_ord = z_abs - z_bas
     e_ord = h_abs * np.radians(d_ord)
-    h_ord = np.sqrt(h_ord ** 2 - e_ord ** 2)
+    h_ord = np.sqrt(h_ord**2 - e_ord**2)
     return (h_ord, e_ord, z_ord)