diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f344683..a996d67 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -38,3 +38,10 @@ jobs:
       run: |
         pytest -s -rxs -vv -Werror tests/ --mpl --mpl-generate-summary=html \
         --mpl-results-path="windrose_test_output-${{ matrix.os }}-${{ matrix.python-version }}"
+    - name: Store mpl-results
+      uses: actions/upload-artifact@v4
+      if: failure()
+      with:
+        name: "windrose_test_output-${{ matrix.os }}-${{ matrix.python-version }}"
+        path: "windrose_test_output-${{ matrix.os }}-${{ matrix.python-version }}"
+        retention-days: 1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 498cc93..7392ede 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,11 @@
 All notable changes to this code base will be documented in this file,
 in every released version.
 
+### Version 1.x.x (unreleased)
+
+## What's Changed
+* Fix issue where sometimes the plot sectors showed a straight line instead of a curved one (#137)
+
 ### Version 1.7.0
 
 ## What's Changed
diff --git a/tests/output/df/test_bar.png b/tests/output/df/test_bar.png
index ca8b802..42c7621 100644
Binary files a/tests/output/df/test_bar.png and b/tests/output/df/test_bar.png differ
diff --git a/tests/output/df/test_box.png b/tests/output/df/test_box.png
index 2fcb3be..e41fefd 100644
Binary files a/tests/output/df/test_box.png and b/tests/output/df/test_box.png differ
diff --git a/tests/output/func/test_wrbox.png b/tests/output/func/test_wrbox.png
index 3fd7c48..2a60b90 100644
Binary files a/tests/output/func/test_wrbox.png and b/tests/output/func/test_wrbox.png differ
diff --git a/tests/output/oo/test_windrose_stacked_histogram_normed.png b/tests/output/oo/test_windrose_stacked_histogram_normed.png
index ca8b802..42c7621 100644
Binary files a/tests/output/oo/test_windrose_stacked_histogram_normed.png and b/tests/output/oo/test_windrose_stacked_histogram_normed.png differ
diff --git a/tests/output/oo/test_windrose_stacked_histogram_normed_calm_limit.png b/tests/output/oo/test_windrose_stacked_histogram_normed_calm_limit.png
index 5a7f277..8526f40 100644
Binary files a/tests/output/oo/test_windrose_stacked_histogram_normed_calm_limit.png and b/tests/output/oo/test_windrose_stacked_histogram_normed_calm_limit.png differ
diff --git a/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned.png b/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned.png
index 3fd7c48..2a60b90 100644
Binary files a/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned.png and b/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned.png differ
diff --git a/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned_calm_limit.png b/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned_calm_limit.png
index be8630c..a2095e6 100644
Binary files a/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned_calm_limit.png and b/tests/output/oo/test_windrose_stacked_histogram_not_normed_binned_calm_limit.png differ
diff --git a/tests/output/test_bar_from_factory.png b/tests/output/test_bar_from_factory.png
index ca8b802..42c7621 100644
Binary files a/tests/output/test_bar_from_factory.png and b/tests/output/test_bar_from_factory.png differ
diff --git a/windrose/windrose.py b/windrose/windrose.py
index 988ba25..cb3c68b 100644
--- a/windrose/windrose.py
+++ b/windrose/windrose.py
@@ -642,6 +642,8 @@ def bar(self, direction, var, **kwargs):
                     zorder=zorder,
                     **kwargs,
                 )
+                # needed so the the line of the rectangle becomes curved
+                patch.get_path()._interpolation_steps = 100
                 self.add_patch(patch)
                 if j == 0:
                     self.patches_list.append(patch)
@@ -718,6 +720,8 @@ def box(self, direction, var, **kwargs):
                     zorder=zorder,
                     **kwargs,
                 )
+                # needed so the the line of the rectangle becomes curved
+                patch.get_path()._interpolation_steps = 100
                 self.add_patch(patch)
                 if j == 0:
                     self.patches_list.append(patch)