diff --git a/.github/workflows/run-crt-test.yml b/.github/workflows/run-crt-test.yml
index 1e20b57f..85748d20 100644
--- a/.github/workflows/run-crt-test.yml
+++ b/.github/workflows/run-crt-test.yml
@@ -8,11 +8,12 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: '${{ matrix.os }}'
     strategy:
       fail-fast: false
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
     - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index de4bb8ef..9678ca6f 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -10,12 +10,12 @@ permissions:
 
 jobs:
   build:
-
-    runs-on: ubuntu-latest
+    runs-on: '${{ matrix.os }}'
     strategy:
       fail-fast: false
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
     - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3
diff --git a/requirements-dev-lock.txt b/requirements-dev-lock.txt
index d0972326..2e2375da 100644
--- a/requirements-dev-lock.txt
+++ b/requirements-dev-lock.txt
@@ -7,9 +7,9 @@
 atomicwrites==1.4.1 \
     --hash=sha256:81b2c9071a49367a7f770170e5eec8cb66567cfbbc8c73d20ce5ca4a8d71cf11
     # via -r requirements-dev.txt
-colorama==0.4.5 \
-    --hash=sha256:854bf444933e37f5824ae7bfc1e98d5bce2ebe4160d46b5edf346a89358e99da \
-    --hash=sha256:e6c6b4334fc50988a639d9b98aa429a0b57da6e17b9a44f0451f930b6967b7a4
+colorama==0.4.6 \
+    --hash=sha256:08695f5cb7ed6e0531a20572697297273c47b8cae5a63ffc6d6ed5c201be6e44 \
+    --hash=sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6
     # via -r requirements-dev.txt
 coverage[toml]==7.2.7 \
     --hash=sha256:06a9a2be0b5b576c3f18f1a241f0473575c4a26021b52b2a85263a00f034d51f \
@@ -75,37 +75,40 @@ coverage[toml]==7.2.7 \
     # via
     #   -r requirements-dev.txt
     #   pytest-cov
-exceptiongroup==1.1.3 \
-    --hash=sha256:097acd85d473d75af5bb98e41b61ff7fe35efe6675e4f9370ec6ec5126d160e9 \
-    --hash=sha256:343280667a4585d195ca1cf9cef84a4e178c4b6cf2274caef9859782b567d5e3
+exceptiongroup==1.2.0 \
+    --hash=sha256:4bfd3996ac73b41e9b9628b04e079f193850720ea5945fc96a08633c66912f14 \
+    --hash=sha256:91f5c769735f051a4290d52edd0858999b57e5876e9f85937691bd4c9fa3ed68
     # via pytest
-iniconfig==1.1.1 \
-    --hash=sha256:011e24c64b7f47f6ebd835bb12a743f2fbe9a26d4cecaa7f53bc4f35ee9da8b3 \
-    --hash=sha256:bc3af051d7d14b2ee5ef9969666def0cd1a000e121eaea580d4a313df4b37f32
+iniconfig==2.0.0 \
+    --hash=sha256:2d91e135bf72d31a410b17c16da610a82cb55f6b0477d1a902134b24a455b8b3 \
+    --hash=sha256:b6a85871a79d2e3b22d2d1b94ac2824226a63c6b741c88f7ae975f18b6778374
     # via pytest
-packaging==21.3 \
-    --hash=sha256:dd47c42927d89ab911e606518907cc2d3a1f38bbd026385970643f9c5b8ecfeb \
-    --hash=sha256:ef103e05f519cdc783ae24ea4e2e0f508a9c99b2d4969652eed6a2e1ea5bd522
+packaging==24.0 \
+    --hash=sha256:2ddfb553fdf02fb784c234c7ba6ccc288296ceabec964ad2eae3777778130bc5 \
+    --hash=sha256:eb82c5e3e56209074766e6885bb04b8c38a0c015d0a30036ebe7ece34c9989e9
     # via pytest
 pluggy==1.4.0 \
     --hash=sha256:7db9f7b503d67d1c5b95f59773ebb58a8c1c288129a88665838012cfb07b8981 \
     --hash=sha256:8c85c2876142a764e5b7548e7d9a0e0ddb46f5185161049a79b7e974454223be
     # via pytest
-psutil==4.4.2 \
-    --hash=sha256:10fbb631142a3200623f4ab49f8bf82c32b79b8fe179f6056d01da3dfc589da1 \
-    --hash=sha256:15aba78f0262d7839702913f5d2ce1e97c89e31456bb26da1a5f9f7d7fe6d336 \
-    --hash=sha256:1c37e6428f7fe3aeea607f9249986d9bb933bb98133c7919837fd9aac4996b07 \
-    --hash=sha256:69e30d789c495b781f7cd47c13ee64452c58abfc7132d6dd1b389af312a78239 \
-    --hash=sha256:7481f299ae0e966a10cb8dd93a327efd8f51995d9bdc8810dcc65d3b12d856ee \
-    --hash=sha256:c2b0d8d1d8b5669b9884d0dd49ccb4094d163858d672d3d13a3fa817bc8a3197 \
-    --hash=sha256:d96d31d83781c7f3d0df8ccb1cc50650ca84d4722c5070b71ce8f1cc112e02e0 \
-    --hash=sha256:e423dd9cb12256c742d1d56ec38bc7d2a7fa09287c82c41e475e68b9f932c2af \
-    --hash=sha256:e44d6b758a96539e3e02336430d3f85263d43c470c5bad93572e9b6a86c67f76
+psutil==5.9.8 \
+    --hash=sha256:02615ed8c5ea222323408ceba16c60e99c3f91639b07da6373fb7e6539abc56d \
+    --hash=sha256:05806de88103b25903dff19bb6692bd2e714ccf9e668d050d144012055cbca73 \
+    --hash=sha256:26bd09967ae00920df88e0352a91cff1a78f8d69b3ecabbfe733610c0af486c8 \
+    --hash=sha256:27cc40c3493bb10de1be4b3f07cae4c010ce715290a5be22b98493509c6299e2 \
+    --hash=sha256:36f435891adb138ed3c9e58c6af3e2e6ca9ac2f365efe1f9cfef2794e6c93b4e \
+    --hash=sha256:50187900d73c1381ba1454cf40308c2bf6f34268518b3f36a9b663ca87e65e36 \
+    --hash=sha256:611052c4bc70432ec770d5d54f64206aa7203a101ec273a0cd82418c86503bb7 \
+    --hash=sha256:6be126e3225486dff286a8fb9a06246a5253f4c7c53b475ea5f5ac934e64194c \
+    --hash=sha256:7d79560ad97af658a0f6adfef8b834b53f64746d45b403f225b85c5c2c140eee \
+    --hash=sha256:8cb6403ce6d8e047495a701dc7c5bd788add903f8986d523e3e20b98b733e421 \
+    --hash=sha256:8db4c1b57507eef143a15a6884ca10f7c73876cdf5d51e713151c1236a0e68cf \
+    --hash=sha256:aee678c8720623dc456fa20659af736241f575d79429a0e5e9cf88ae0605cc81 \
+    --hash=sha256:bc56c2a1b0d15aa3eaa5a60c9f3f8e3e565303b465dbf57a1b730e7a2b9844e0 \
+    --hash=sha256:bd1184ceb3f87651a67b2708d4c3338e9b10c5df903f2e3776b62303b26cb631 \
+    --hash=sha256:d06016f7f8625a1825ba3732081d77c94589dca78b7a3fc072194851e88461a4 \
+    --hash=sha256:d16bbddf0693323b8c6123dd804100241da461e41d6e332fb0ba6058f630f8c8
     # via -r requirements-dev.txt
-pyparsing==3.0.9 \
-    --hash=sha256:2b020ecf7d21b687f219b71ecad3631f644a47f01403fa1d1036b0c6416d70fb \
-    --hash=sha256:5026bae9a10eeaefb61dab2f09052b9f4307d44aee4eda64b309723d8d206bbc
-    # via packaging
 pytest==8.1.1 \
     --hash=sha256:2a8386cfc11fa9d2c50ee7b2a57e7d898ef90470a7a34c4b949ff59662bb78b7 \
     --hash=sha256:ac978141a75948948817d360297b7aae0fcb9d6ff6bc9ec6d514b85d5a65c044
diff --git a/requirements-dev.txt b/requirements-dev.txt
index eb837d8e..79eac21f 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,4 +1,4 @@
-psutil>=4.1.0,<5.0.0
+psutil>=4.1.0,<6.0.0
 tabulate==0.7.5
 coverage==7.2.7
 wheel==0.43.0
diff --git a/tests/unit/test_compat.py b/tests/unit/test_compat.py
index f40a602a..5c2a8042 100644
--- a/tests/unit/test_compat.py
+++ b/tests/unit/test_compat.py
@@ -13,6 +13,7 @@
 import os
 import shutil
 import signal
+import sys
 import tempfile
 from io import BytesIO
 
@@ -79,6 +80,17 @@ def test_non_file_like_obj(self):
 
 class TestBaseManager(unittest.TestCase):
     def create_pid_manager(self):
+        if sys.platform == "darwin":
+            import multiprocessing
+
+            # Starting in Python 3.8, the default multiprocessing
+            # moved from `fork` to `spawn` to account for how macOS
+            # handles (or doesn't) forking. Users who are hitting this
+            # issue _may_ consider changing the start_method after
+            # reviewing this issue.
+            # https://github.com/python/cpython/issues/77906
+            multiprocessing.set_start_method("fork")
+
         class PIDManager(BaseManager):
             pass