diff --git a/lib/cartopy/mpl/gridliner.py b/lib/cartopy/mpl/gridliner.py
index 627e95ae6..1b1672cba 100644
--- a/lib/cartopy/mpl/gridliner.py
+++ b/lib/cartopy/mpl/gridliner.py
@@ -19,8 +19,8 @@
 
 import cartopy
 from cartopy.crs import PlateCarree, Projection, _RectangularProjection
-from cartopy.mpl.ticker import (LatitudeFormatter, LatitudeLocator,
-                                LongitudeFormatter, LongitudeLocator)
+from cartopy.mpl.ticker import (LatitudeFormatter, LatitudeLocator, LongitudeFormatter,
+                                LongitudeLocator)
 
 
 degree_locator = mticker.MaxNLocator(nbins=9, steps=[1, 1.5, 1.8, 2, 3, 6, 10])
diff --git a/lib/cartopy/tests/mpl/test_axes.py b/lib/cartopy/tests/mpl/test_axes.py
index 559c838a7..2546c98be 100644
--- a/lib/cartopy/tests/mpl/test_axes.py
+++ b/lib/cartopy/tests/mpl/test_axes.py
@@ -13,8 +13,7 @@
 
 import cartopy.crs as ccrs
 import cartopy.feature as cfeature
-from cartopy.mpl.geoaxes import (GeoAxes, GeoAxesSubplot,
-                                 InterProjectionTransform)
+from cartopy.mpl.geoaxes import GeoAxes, GeoAxesSubplot, InterProjectionTransform
 
 
 class TestNoSpherical:
diff --git a/lib/cartopy/tests/mpl/test_gridliner.py b/lib/cartopy/tests/mpl/test_gridliner.py
index a3dee2e67..76c339fd8 100644
--- a/lib/cartopy/tests/mpl/test_gridliner.py
+++ b/lib/cartopy/tests/mpl/test_gridliner.py
@@ -16,9 +16,8 @@
 import cartopy.crs as ccrs
 from cartopy.mpl import _MPL_36
 from cartopy.mpl.geoaxes import GeoAxes
-from cartopy.mpl.gridliner import (LATITUDE_FORMATTER, LONGITUDE_FORMATTER,
-                                   Gridliner, classic_formatter,
-                                   classic_locator)
+from cartopy.mpl.gridliner import (LATITUDE_FORMATTER, LONGITUDE_FORMATTER, Gridliner,
+                                   classic_formatter, classic_locator)
 from cartopy.mpl.ticker import LongitudeFormatter, LongitudeLocator
 
 
diff --git a/lib/cartopy/tests/mpl/test_ticker.py b/lib/cartopy/tests/mpl/test_ticker.py
index 7e9020e9d..7d42ab1ba 100644
--- a/lib/cartopy/tests/mpl/test_ticker.py
+++ b/lib/cartopy/tests/mpl/test_ticker.py
@@ -12,8 +12,8 @@
 
 import cartopy.crs as ccrs
 from cartopy.mpl.geoaxes import GeoAxes
-from cartopy.mpl.ticker import (LatitudeFormatter, LatitudeLocator,
-                                LongitudeFormatter, LongitudeLocator)
+from cartopy.mpl.ticker import (LatitudeFormatter, LatitudeLocator, LongitudeFormatter,
+                                LongitudeLocator)
 
 
 ONE_MIN = 1 / 60.
diff --git a/pyproject.toml b/pyproject.toml
index b4cfc58fa..da23c5a00 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -89,6 +89,7 @@ ignore = [
 force_sort_within_sections = true
 known_first_party = "cartopy"
 lines_after_imports = 2
+line_length = 88
 no_lines_before = "LOCALFOLDER"
 skip_gitignore = true
 verbose = false
diff --git a/setup.cfg b/setup.cfg
index ce9c43405..124e0715b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,4 +1,5 @@
 [flake8]
+max-line-length = 88
 exclude = \
     build, \
     setup.py, \