diff --git a/testing/web-platform/tests/tools/serve/test_functional.py b/testing/web-platform/tests/tools/serve/test_functional.py
index b2a09068ce76..0e7ed78e8d6f 100644
--- a/testing/web-platform/tests/tools/serve/test_functional.py
+++ b/testing/web-platform/tests/tools/serve/test_functional.py
@@ -41,6 +41,8 @@
 import
 queue
 import
+sys
+import
 tempfile
 import
 threading
@@ -188,6 +190,50 @@
 (
 name
 )
+pytest
+.
+mark
+.
+skipif
+(
+sys
+.
+version_info
+>
+=
+(
+3
+8
+)
+and
+sys
+.
+platform
+=
+=
+'
+darwin
+'
+                    
+reason
+=
+"
+multiprocessing
+test
+hangs
+in
+Python
+3
+.
+8
+on
+macOS
+(
+#
+24880
+)
+"
+)
 def
 test_subprocess_exit
 (
diff --git a/testing/web-platform/tests/tools/wpt/tests/test_wpt.py b/testing/web-platform/tests/tools/wpt/tests/test_wpt.py
index 63eb912d7ca3..041edbc95ff6 100644
--- a/testing/web-platform/tests/tools/wpt/tests/test_wpt.py
+++ b/testing/web-platform/tests/tools/wpt/tests/test_wpt.py
@@ -1461,6 +1461,50 @@
 mark
 .
 remote_network
+pytest
+.
+mark
+.
+skipif
+(
+sys
+.
+version_info
+>
+=
+(
+3
+8
+)
+and
+sys
+.
+platform
+=
+=
+'
+darwin
+'
+                    
+reason
+=
+"
+multiprocessing
+test
+hangs
+in
+Python
+3
+.
+8
+on
+macOS
+(
+#
+24880
+)
+"
+)
 def
 test_run_failing_test
 (
@@ -1719,6 +1763,50 @@
 mark
 .
 remote_network
+pytest
+.
+mark
+.
+skipif
+(
+sys
+.
+version_info
+>
+=
+(
+3
+8
+)
+and
+sys
+.
+platform
+=
+=
+'
+darwin
+'
+                    
+reason
+=
+"
+multiprocessing
+test
+hangs
+in
+Python
+3
+.
+8
+on
+macOS
+(
+#
+24880
+)
+"
+)
 def
 test_run_verify_unstable
 (
diff --git a/testing/web-platform/tests/tools/wptserve/tests/functional/test_stash.py b/testing/web-platform/tests/tools/wptserve/tests/functional/test_stash.py
index a3bd59063e9c..74a48ac67f6c 100644
--- a/testing/web-platform/tests/tools/wptserve/tests/functional/test_stash.py
+++ b/testing/web-platform/tests/tools/wptserve/tests/functional/test_stash.py
@@ -1,4 +1,6 @@
 import
+sys
+import
 unittest
 import
 uuid
@@ -31,6 +33,50 @@
 base
 import
 TestUsingServer
+pytest
+.
+mark
+.
+skipif
+(
+sys
+.
+version_info
+>
+=
+(
+3
+8
+)
+and
+sys
+.
+platform
+=
+=
+'
+darwin
+'
+                    
+reason
+=
+"
+multiprocessing
+test
+hangs
+in
+Python
+3
+.
+8
+on
+macOS
+(
+#
+24880
+)
+"
+)
 class
 TestResponseSetCookie
 (