diff --git a/pyproject.toml b/pyproject.toml
index 6330a63f..ca2b8d9a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,7 +44,7 @@ test = [
     "ipywidgets",
     # needed by ipywidgets >= 8.0.6
     "ipykernel",
-    "PyQt6",
+    "PySide6",
     "joblib",
     "jacobi",
     "matplotlib",
diff --git a/src/iminuit/minuit.py b/src/iminuit/minuit.py
index ee63b064..ff98bd4b 100644
--- a/src/iminuit/minuit.py
+++ b/src/iminuit/minuit.py
@@ -2343,7 +2343,7 @@ def interactive(
         """
         Interactive GUI for fitting.
 
-        Starts a fitting application (requires PyQt6, matplotlib) in which the
+        Starts a fitting application (requires PySide6, matplotlib) in which the
         fit is visualized and the parameters can be manipulated to find good
         starting parameters and to debug the fit.
 
diff --git a/src/iminuit/qtwidget.py b/src/iminuit/qtwidget.py
index f54e0207..ee8639af 100644
--- a/src/iminuit/qtwidget.py
+++ b/src/iminuit/qtwidget.py
@@ -1,4 +1,4 @@
-"""Interactive fitting widget using PyQt6."""
+"""Interactive fitting widget using PySide6."""
 
 from .util import _widget_guess_initial_step, _make_finite
 import warnings
@@ -7,12 +7,12 @@
 from contextlib import contextmanager
 
 try:
-    from PyQt6 import QtCore, QtGui, QtWidgets
+    from PySide6 import QtCore, QtGui, QtWidgets
     from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg
     from matplotlib import pyplot as plt
 except ModuleNotFoundError as e:
     e.msg += (
-        "\n\nPlease install PyQt6, and matplotlib to enable interactive "
+        "\n\nPlease install PySide6, and matplotlib to enable interactive "
         "outside of Jupyter notebooks."
     )
     raise
diff --git a/tests/test_qtwidget.py b/tests/test_qtwidget.py
index 0e3e16aa..b5bd3677 100644
--- a/tests/test_qtwidget.py
+++ b/tests/test_qtwidget.py
@@ -5,7 +5,7 @@
 
 mpl = pytest.importorskip("matplotlib")
 plt = pytest.importorskip("matplotlib.pyplot")
-PyQt6 = pytest.importorskip("PyQt6")
+PySide6 = pytest.importorskip("PySide6")
 
 mpl.use("Agg")
 
@@ -17,7 +17,7 @@ def qtinteractive(m, plot=None, raise_on_exception=False, **kwargs):
 
 
 @pytest.mark.filterwarnings("ignore::DeprecationWarning")
-def test_interactive_pyqt6(qtbot):
+def test_interactive_pyside6(qtbot):
     def cost(a, b):
         return a**2 + b**2
 
@@ -44,7 +44,7 @@ def assert_call(self):
     with plot.assert_call():
         mw1 = qtinteractive(m, plot)
     qtbot.addWidget(mw1)
-    assert isinstance(mw1, PyQt6.QtWidgets.QWidget)
+    assert isinstance(mw1, PySide6.QtWidgets.QWidget)
 
     # manipulate state to also check this code
     with plot.assert_call():
@@ -119,7 +119,7 @@ def __call__(self, a, b):
 
 
 @pytest.mark.filterwarnings("ignore::DeprecationWarning")
-def test_interactive_pyqt6_raises(qtbot):
+def test_interactive_pyside6_raises(qtbot):
     def raiser(args):
         raise ValueError
 
@@ -133,7 +133,7 @@ def raiser(args):
 
 
 @pytest.mark.filterwarnings("ignore::DeprecationWarning")
-def test_interactive_pyqt6_with_array_func(qtbot):
+def test_interactive_pyside6_with_array_func(qtbot):
     def cost(par):
         return par[0] ** 2 + (par[1] / 2) ** 2
 
diff --git a/tests/test_without_pyqt6.py b/tests/test_without_pyside6.py
similarity index 69%
rename from tests/test_without_pyqt6.py
rename to tests/test_without_pyside6.py
index 49345770..db048811 100644
--- a/tests/test_without_pyqt6.py
+++ b/tests/test_without_pyside6.py
@@ -5,22 +5,22 @@
 pytest.importorskip("matplotlib")
 
 
-def test_pyqt6_interactive_with_ipython():
+def test_pyside6_interactive_with_ipython():
     pytest.importorskip("IPython")
     import iminuit
 
     cost = LeastSquares([1.1, 2.2], [3.3, 4.4], 1, lambda x, a: a * x)
 
-    with hide_modules("PyQt6", reload="iminuit.qtwidget"):
-        with pytest.raises(ModuleNotFoundError, match="Please install PyQt6"):
+    with hide_modules("PySide6", reload="iminuit.qtwidget"):
+        with pytest.raises(ModuleNotFoundError, match="Please install PySide6"):
             iminuit.Minuit(cost, 1).interactive()
 
 
-def test_pyqt6_interactive_without_ipython():
+def test_pyside6_interactive_without_ipython():
     import iminuit
 
     cost = LeastSquares([1.1, 2.2], [3.3, 4.4], 1, lambda x, a: a * x)
 
-    with hide_modules("PyQt6", "IPython", reload="iminuit.qtwidget"):
-        with pytest.raises(ModuleNotFoundError, match="Please install PyQt6"):
+    with hide_modules("PySide6", "IPython", reload="iminuit.qtwidget"):
+        with pytest.raises(ModuleNotFoundError, match="Please install PySide6"):
             iminuit.Minuit(cost, 1).interactive()