diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index 0070f905..c1ae7c22 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -30,10 +30,10 @@ jobs:
 
       # Used to host cibuildwheel
       - name: Build wheel
-        uses: pypa/cibuildwheel@v3.3.1
+        uses: pypa/cibuildwheel@v3.4.0
         with:
           output-dir: wheelhouse
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: cibw-wheels-${{ matrix.os }}
           path: ./wheelhouse/*.whl
@@ -49,7 +49,7 @@ jobs:
         run: source etc/make-libsemigroups.sh && sudo make install
       - name: Build SDist
         run: uv build --sdist
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: sdist
           path: dist/*.tar.gz
@@ -73,7 +73,7 @@ jobs:
 
     steps:
       - name: Download wheels and sdist artifacts
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           # Here, we could specify a name of an artifact, or a pattern that
           # matches the names of artifacts. However, by not specifying these
diff --git a/build_tools/__init__.py b/build_tools/__init__.py
index f5a48a3a..267ba36d 100644
--- a/build_tools/__init__.py
+++ b/build_tools/__init__.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2021-2024 J. D. Mitchell
+# Copyright (c) 2021-2026 J. D. Mitchell
 #
 # Distributed under the terms of the GPL license version 3.
 #
@@ -11,4 +11,4 @@ def minimum_libsemigroups_version():
     """Returns the minimum required version of libsemigroups required to build
     libsemigroups_pybind11.
     """
-    return "3.5.1"
+    return "3.5.3"
diff --git a/src/cong.cpp b/src/cong.cpp
index 7a439b69..53599009 100644
--- a/src/cong.cpp
+++ b/src/cong.cpp
@@ -67,9 +67,7 @@ individual algorithms, such as :any:`Kambites`,
     >>> cong = Congruence(congruence_kind.twosided, p)
     >>> is_obviously_infinite(cong)
     True
-    >>> cong.add_generating_pair([1, 1, 1], [])
-    <2-sided Congruence over <monoid presentation with 2 letters, 1 rule, and length 2> with 1 gen. pair, 4 runners>
-    >>> cong.number_of_classes()
+    >>> cong.add_generating_pair([1, 1, 1], []).number_of_classes()
     3
     >>> is_obviously_infinite(cong)
     False
diff --git a/tests/test_cong.py b/tests/test_cong.py
index cb9b4e1f..61766e71 100644
--- a/tests/test_cong.py
+++ b/tests/test_cong.py
@@ -93,9 +93,9 @@ def test_has_get():
 
     c = Congruence(congruence_kind.twosided, p)
 
-    assert c.number_of_runners() == 4
-    assert c.has(ToddCoxeter)
-    tc = c.get(ToddCoxeter)
+    assert c.number_of_runners() <= 4
+    assert c.has(Kambites)
+    k = c.get(Kambites)
 
     c.run()
     assert c.number_of_classes() == POSITIVE_INFINITY
@@ -104,12 +104,12 @@ def test_has_get():
     assert c.has(KnuthBendix)
     assert c.get(KnuthBendix).confluent()
 
-    # Check that the ToddCoxeter returned above outlives its deletion in
+    # Check that the Kambites returned above outlives its deletion in
     # Congruence
-    assert tc.number_of_classes() == POSITIVE_INFINITY
+    assert k.small_overlap_class() == 1
 
     with pytest.raises(LibsemigroupsError):
-        c.get(ToddCoxeter)
+        c.get(Kambites)
 
 
 def test_normal_forms():