diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f4718678..0bce461c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -27,7 +27,7 @@ jobs:
       # Ensure that a wheel builder finishes even if another fails
       fail-fast: false
       matrix:
-        python-version: [3.9, '3.10', '3.11']
+        python-version: [3.9, '3.10', '3.11', '3.12']
         MINIMUM_REQUIREMENTS: [0]
         USE_SCIPY: [0]
         USE_SDIST: [0]
@@ -56,6 +56,13 @@ jobs:
             python-version: '3.11'
             PIP_FLAGS: "--pre"
             OPTIONS_NAME: "pre-releases"
+          - platform_id: manylinux_x86_64
+            python-version: '3.12'
+            PIP_FLAGS: "--pre"
+            OPTIONS_NAME: "pre-releases"
+        exclude:
+          - python-version: '3.12'
+            PIP_FLAGS: [""]
 
     steps:
       - name: Checkout PyWavelets
@@ -65,6 +72,7 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version}}
+          allow-prereleases: true
 
       - name: Build package
         env:
@@ -90,11 +98,11 @@ jobs:
                 pip install ${NUMPY_MIN}
                 if [ "${USE_SCIPY}" == "1" ]; then pip install ${SCIPY_MIN}; fi
             else
-                pip install cython
-                pip install numpy
-                if [ "${USE_SCIPY}" == "1" ]; then pip install scipy; fi
+                pip install ${PIP_FLAGS} cython
+                pip install ${PIP_FLAGS} numpy
+                if [ "${USE_SCIPY}" == "1" ]; then pip install ${PIP_FLAGS} scipy; fi
             fi
-            pip install matplotlib pytest
+            pip install ${PIP_FLAGS} matplotlib pytest
 
             set -o pipefail
             if [ "${USE_WHEEL}" == "1" ]; then
@@ -113,7 +121,6 @@ jobs:
 
       - name: Run tests
         env:
-            PIP_FLAGS: ${{ matrix.PIP_FLAGS }}
             USE_WHEEL: ${{ matrix.USE_WHEEL }}
             USE_SDIST: ${{ matrix.USE_SDIST }}
             REFGUIDE_CHECK: ${{ matrix.REFGUIDE_CHECK }}
@@ -150,7 +157,7 @@ jobs:
       # Ensure that a wheel builder finishes even if another fails
       fail-fast: false
       matrix:
-        python-version: [3.9, '3.11']
+        python-version: [3.9, '3.11', '3.12']
         MINIMUM_REQUIREMENTS: [0]
         USE_SCIPY: [0]
         USE_SDIST: [0]
@@ -165,6 +172,12 @@ jobs:
           - python-version: '3.11'
             PIP_FLAGS: "--pre"
             OPTIONS_NAME: "pre-releases"
+          - python-version: '3.12'
+            PIP_FLAGS: "--pre"
+            OPTIONS_NAME: "pre-releases"
+        exclude:
+          - python-version: '3.12'
+            PIP_FLAGS: [""]
 
     steps:
       - name: Checkout PyWavelets
@@ -174,6 +187,7 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version}}
+          allow-prereleases: true
 
       - name: Build package
         env:
@@ -198,10 +212,10 @@ jobs:
                 pip install ${CYTHON_MIN} ${NUMPY_MIN}
                 if [ "${USE_SCIPY}" == "1" ]; then pip install ${SCIPY_MIN}; fi
             else
-                pip install cython numpy
-                if [ "${USE_SCIPY}" == "1" ]; then pip install scipy; fi
+                pip install ${PIP_FLAGS} cython numpy
+                if [ "${USE_SCIPY}" == "1" ]; then pip install ${PIP_FLAGS} scipy; fi
             fi
-            pip install matplotlib pytest
+            pip install ${PIP_FLAGS} matplotlib pytest
 
             set -o pipefail
             if [ "${USE_WHEEL}" == "1" ]; then
diff --git a/pyproject.toml b/pyproject.toml
index 75b17496..f9b44314 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ requires = [
     # For Python versions which aren't yet officially supported, we specify an
     # unpinned NumPy which allows source distributions to be used and allows
     # wheels to be used as soon as they become available.
-    "numpy>=1.26.0b1; python_version>='3.12rc2'",
+    "numpy>=1.26.0b1; python_version>='3.12'",
     "numpy; python_version>='3.9' and platform_python_implementation=='PyPy'",
 ]
 
diff --git a/pywt/tests/test_wavelet.py b/pywt/tests/test_wavelet.py
index e3f1addb..00346100 100644
--- a/pywt/tests/test_wavelet.py
+++ b/pywt/tests/test_wavelet.py
@@ -171,8 +171,8 @@ def test_custom_wavelet():
                                 filter_bank=filter_bank)
 
     # check expected default wavelet properties
-    assert_(~haar_custom2.orthogonal)
-    assert_(~haar_custom2.biorthogonal)
+    assert_(not haar_custom2.orthogonal)
+    assert_(not haar_custom2.biorthogonal)
     assert_(haar_custom2.symmetry == 'unknown')
     assert_(haar_custom2.family_name == '')
     assert_(haar_custom2.short_family_name == '')