matplotlib · timhoffm · Sep 23, 2022 · Sep 23, 2022
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -2426,9 +2426,12 @@ def __init__(self,
             if isinstance(tight_layout, dict):
                 self.get_layout_engine().set(**tight_layout)
         elif constrained_layout is not None:
-            self.set_layout_engine(layout='constrained')
             if isinstance(constrained_layout, dict):
+                self.set_layout_engine(layout='constrained')
                 self.get_layout_engine().set(**constrained_layout)
+            elif constrained_layout:
+                self.set_layout_engine(layout='constrained')
+
         else:
             # everything is None, so use default:
             self.set_layout_engine(layout=layout)

diff --git a/lib/matplotlib/tests/test_constrainedlayout.py b/lib/matplotlib/tests/test_constrainedlayout.py
@@ -656,3 +656,14 @@ def test_compressed1():
     pos = axs[1, 2].get_position()
     np.testing.assert_allclose(pos.x1, 0.8618, atol=1e-3)
     np.testing.assert_allclose(pos.y0, 0.1934, atol=1e-3)
+
+
+@pytest.mark.parametrize('arg, state', [
+    (True, True),
+    (False, False),
+    ({}, True),
+    ({'rect': None}, True)
+])
+def test_set_constrained_layout(arg, state):
+    fig, ax = plt.subplots(constrained_layout=arg)
+    assert fig.get_constrained_layout() is state