diff --git a/ultraplot/axes/plot.py b/ultraplot/axes/plot.py
index 78531dcc..17da6e2e 100644
--- a/ultraplot/axes/plot.py
+++ b/ultraplot/axes/plot.py
@@ -1467,8 +1467,7 @@ def _add_contour_labels(
         on unfilled contour object (otherwise errors crop up).
         """
         # Parse input args
-        zorder = max((h.get_zorder() for h in obj.collections), default=3)
-        zorder = max(3, zorder + 1)
+        zorder = max(3, obj.get_zorder() + 1)
         kwargs.setdefault("zorder", zorder)
         colors = _not_none(c=c, color=color, colors=colors)
         fontsize = _not_none(size=size, fontsize=fontsize, default=rc["font.smallsize"])
@@ -1808,10 +1807,11 @@ def _fix_patch_edges(obj, edgefix=None, **kwargs):
                 obj.set_linewidth(linewidth)
                 obj.set_edgecolor("face")
 
-                for contour in obj.collections:
-                    contour.set_linestyle("-")
-                    contour.set_linewidth(linewidth)
-                    contour.set_edgecolor("face")
+                import matplotlib.patheffects as pe
+
+                obj.set_path_effects(
+                    [pe.Stroke(linewidth=linewidth, linestyle="-", foreground="face")]
+                )
         elif isinstance(obj, mcollections.Collection):  # e.g. QuadMesh, PolyCollection
             obj.set_linewidth(linewidth)
             obj.set_edgecolor("face")
diff --git a/ultraplot/tests/test_1dplots.py b/ultraplot/tests/test_1dplots.py
index 6eb0ef40..60eed6d0 100644
--- a/ultraplot/tests/test_1dplots.py
+++ b/ultraplot/tests/test_1dplots.py
@@ -412,7 +412,7 @@ def test_triplot_variants(x, y, z, triangles, use_triangulation, use_datadict):
         ax.tricontourf(triangulation, z, levels=64, cmap="PuBu")
     elif use_datadict:
         ax.tricontourf("x", "y", "z", data=df)
-        return
+        return fig
     else:
         # Use direct x, y, z inputs
         ax.tricontourf(x, y, z, triangles=triangles, levels=64, cmap="PuBu")
diff --git a/ultraplot/tests/test_2dplots.py b/ultraplot/tests/test_2dplots.py
index 5ae805a4..823484d2 100644
--- a/ultraplot/tests/test_2dplots.py
+++ b/ultraplot/tests/test_2dplots.py
@@ -123,9 +123,10 @@ def test_contour_labels():
     ax = axs[1]
     m = ax.contourf(data)
     ax.clabel(m, colors="black", fontsize="large")  # looks fine without this
-    for o in m.collections:
-        o.set_linewidth(1.5)
-        o.set_edgecolor("k")
+
+    import matplotlib.patheffects as pe
+
+    m.set_path_effects([pe.Stroke(linewidth=1.5, foreground="k"), pe.Normal()])
     return fig
 
 
diff --git a/ultraplot/tests/test_format.py b/ultraplot/tests/test_format.py
index dad3171f..9d8be905 100644
--- a/ultraplot/tests/test_format.py
+++ b/ultraplot/tests/test_format.py
@@ -28,6 +28,8 @@ def test_ignored_keywords():
             subplot_kw={"proj": "cart"},
             subplotpars={"left": 0.2},
         )
+    # only capture ultraplot warnings not general mpl warnings, e.g. deprecation warnings
+    record = [r for r in record if "UltraPlotWarning" in str(r)]
     assert len(record) == 3
     with warnings.catch_warnings(record=True) as record:
         fig.subplots_adjust(left=0.2)