diff --git a/csharp/ql/integration-tests/all-platforms/autobuild/test.py b/csharp/ql/integration-tests/all-platforms/autobuild/test.py
index 6edef5258f88..ccbf8bd9ac68 100644
--- a/csharp/ql/integration-tests/all-platforms/autobuild/test.py
+++ b/csharp/ql/integration-tests/all-platforms/autobuild/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create()
diff --git a/csharp/ql/integration-tests/all-platforms/binlog/test.py b/csharp/ql/integration-tests/all-platforms/binlog/test.py
index d551651fb114..b23d8e407361 100644
--- a/csharp/ql/integration-tests/all-platforms/binlog/test.py
+++ b/csharp/ql/integration-tests/all-platforms/binlog/test.py
@@ -1,6 +1,7 @@
 import commands
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     commands.run(["dotnet", "build", "test.sln", "/bl:test.binlog"])
     codeql.database.create(build_mode="none", extractor_option="binlog=test.binlog")
diff --git a/csharp/ql/integration-tests/all-platforms/binlog_multiple/test.py b/csharp/ql/integration-tests/all-platforms/binlog_multiple/test.py
index 585d86ef57b5..3d46563a79a0 100644
--- a/csharp/ql/integration-tests/all-platforms/binlog_multiple/test.py
+++ b/csharp/ql/integration-tests/all-platforms/binlog_multiple/test.py
@@ -1,6 +1,7 @@
 import commands
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     commands.run(["dotnet", "build", "a/test.csproj", "/bl:a.binlog"])
     commands.run(["dotnet", "build", "b/test.csproj", "/bl:b.binlog"])
diff --git a/csharp/ql/integration-tests/all-platforms/blazor/test.py b/csharp/ql/integration-tests/all-platforms/blazor/test.py
index 90b827ede509..330f0c8e0e85 100644
--- a/csharp/ql/integration-tests/all-platforms/blazor/test.py
+++ b/csharp/ql/integration-tests/all-platforms/blazor/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(source_root="BlazorTest")
diff --git a/csharp/ql/integration-tests/all-platforms/blazor_build_mode_none/test.py b/csharp/ql/integration-tests/all-platforms/blazor_build_mode_none/test.py
index a62769aadbd7..f0e2d3073af6 100644
--- a/csharp/ql/integration-tests/all-platforms/blazor_build_mode_none/test.py
+++ b/csharp/ql/integration-tests/all-platforms/blazor_build_mode_none/test.py
@@ -1,5 +1,7 @@
 import pytest
+import dotnet
 
+@dotnet.xdist_group_if_macos
 @pytest.mark.ql_test("DB-CHECK", xfail=True)
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/blazor_net_8/test.py b/csharp/ql/integration-tests/all-platforms/blazor_net_8/test.py
index 90b827ede509..330f0c8e0e85 100644
--- a/csharp/ql/integration-tests/all-platforms/blazor_net_8/test.py
+++ b/csharp/ql/integration-tests/all-platforms/blazor_net_8/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(source_root="BlazorTest")
diff --git a/csharp/ql/integration-tests/all-platforms/conditional_compilation/test.py b/csharp/ql/integration-tests/all-platforms/conditional_compilation/test.py
index bf69f536b659..7eb44d96ee33 100644
--- a/csharp/ql/integration-tests/all-platforms/conditional_compilation/test.py
+++ b/csharp/ql/integration-tests/all-platforms/conditional_compilation/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     os.environ["CODEQL_EXTRACTOR_CSHARP_OPTION_TRAP_COMPRESSION"] = "none"
     codeql.database.create(
diff --git a/csharp/ql/integration-tests/all-platforms/cshtml/test.py b/csharp/ql/integration-tests/all-platforms/cshtml/test.py
index 7085307904f9..ec19d6061049 100644
--- a/csharp/ql/integration-tests/all-platforms/cshtml/test.py
+++ b/csharp/ql/integration-tests/all-platforms/cshtml/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(command="dotnet build")
diff --git a/csharp/ql/integration-tests/all-platforms/cshtml_standalone/test.py b/csharp/ql/integration-tests/all-platforms/cshtml_standalone/test.py
index 237174a46c6b..5ce95a5c8b53 100644
--- a/csharp/ql/integration-tests/all-platforms/cshtml_standalone/test.py
+++ b/csharp/ql/integration-tests/all-platforms/cshtml_standalone/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_disabled/test.py b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_disabled/test.py
index 88ecf0e513ac..67af9d8a224d 100644
--- a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_disabled/test.py
+++ b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_disabled/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_EXTRACT_WEB_VIEWS"] = "false"
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_flowsteps/test.py b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_flowsteps/test.py
index 237174a46c6b..5ce95a5c8b53 100644
--- a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_flowsteps/test.py
+++ b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_flowsteps/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_net6/test.py b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_net6/test.py
index 237174a46c6b..5ce95a5c8b53 100644
--- a/csharp/ql/integration-tests/all-platforms/cshtml_standalone_net6/test.py
+++ b/csharp/ql/integration-tests/all-platforms/cshtml_standalone_net6/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.py b/csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.py
index a2676d16d9c0..026328cc13f6 100644
--- a/csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.py
+++ b/csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(_assert_failure=True)
diff --git a/csharp/ql/integration-tests/all-platforms/diag_missing_project_files/test.py b/csharp/ql/integration-tests/all-platforms/diag_missing_project_files/test.py
index a2676d16d9c0..026328cc13f6 100644
--- a/csharp/ql/integration-tests/all-platforms/diag_missing_project_files/test.py
+++ b/csharp/ql/integration-tests/all-platforms/diag_missing_project_files/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(_assert_failure=True)
diff --git a/csharp/ql/integration-tests/all-platforms/diag_missing_xamarin_sdk/test.py b/csharp/ql/integration-tests/all-platforms/diag_missing_xamarin_sdk/test.py
index a2676d16d9c0..026328cc13f6 100644
--- a/csharp/ql/integration-tests/all-platforms/diag_missing_xamarin_sdk/test.py
+++ b/csharp/ql/integration-tests/all-platforms/diag_missing_xamarin_sdk/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(_assert_failure=True)
diff --git a/csharp/ql/integration-tests/all-platforms/diag_recursive_generics/test.py b/csharp/ql/integration-tests/all-platforms/diag_recursive_generics/test.py
index 7085307904f9..ec19d6061049 100644
--- a/csharp/ql/integration-tests/all-platforms/diag_recursive_generics/test.py
+++ b/csharp/ql/integration-tests/all-platforms/diag_recursive_generics/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(command="dotnet build")
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_10/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_10/test.py
index 903d34300616..e897cfa82268 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_10/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_10/test.py
@@ -1,5 +1,9 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test1(codeql, csharp):
     codeql.database.create()
 
+@dotnet.xdist_group_if_macos
 def test2(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_build/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_build/test.py
index 75ba09477fa0..5e312369eb74 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_build/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_build/test.py
@@ -1,4 +1,5 @@
 import os
+import dotnet
 
 def check_build_out(msg, s):
     lines = s.splitlines()
@@ -6,11 +7,13 @@ def check_build_out(msg, s):
         any (("[build-stdout]" in line) and (msg in line) for line in lines)
     ), f"The C# tracer did not interpret the dotnet path-to-application command correctly."
 
+@dotnet.xdist_group_if_macos
 def test1(codeql, csharp):
     codeql.database.create(command="dotnet build")
 
 
 # This test checks that we don't inject any flags when running the application using `dotnet`
+@dotnet.xdist_group_if_macos
 def test2(codeql, csharp, cwd):
     s = codeql.database.create(
         command=[
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_no_args_inject/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_no_args_inject/test.py
index d1a7fba48701..cb455496be90 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_no_args_inject/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_no_args_inject/test.py
@@ -1,3 +1,6 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.init("test-db", source_root=".")
     # the tracer configuration should not inject the extra command-line arguments for these commands
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_pack/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_pack/test.py
index fc75ed1870f3..688e8a1d4590 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_pack/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_pack/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(command="dotnet pack -o nugetpackage")
     assert os.path.isfile(
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_publish/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_publish/test.py
index ffe0332d6639..0377869d8375 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_publish/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_publish/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     artifacts = "bin/Temp"
     codeql.database.create(command=f"dotnet publish -o {artifacts}")
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_run/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_run/test.py
index 8740bad71a84..f5257714663e 100644
--- a/csharp/ql/integration-tests/all-platforms/dotnet_run/test.py
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_run/test.py
@@ -1,3 +1,5 @@
+import dotnet
+
 def check_build_out(msg, s):
     lines = s.splitlines()
     assert (
@@ -5,36 +7,42 @@ def check_build_out(msg, s):
     ), "The C# tracer did not interpret the 'dotnet run' command correctly"
 
 # no arguments
+@dotnet.xdist_group_if_macos
 def test_no_args(codeql, csharp):
     s = codeql.database.create(command="dotnet run", _capture="stdout")
     check_build_out("Default reply", s)
 
 
 # no arguments, but `--`
+@dotnet.xdist_group_if_macos
 def test_no_arg_dash_dash(codeql, csharp):
     s = codeql.database.create(command="dotnet run --", _capture="stdout")
     check_build_out("Default reply", s)
 
 
 # one argument, no `--`
+@dotnet.xdist_group_if_macos
 def test_one_arg_no_dash_dash(codeql, csharp):
     s = codeql.database.create(command="dotnet run hello", _capture="stdout")
     check_build_out("Default reply", s)
 
 
 # one argument, but `--`
+@dotnet.xdist_group_if_macos
 def test_one_arg_dash_dash(codeql, csharp):
     s = codeql.database.create(command="dotnet run -- hello", _capture="stdout")
     check_build_out("Default reply", s)
 
 
 # two arguments, no `--`
+@dotnet.xdist_group_if_macos
 def test_two_args_no_dash_dash(codeql, csharp):
     s = codeql.database.create(command="dotnet run hello world", _capture="stdout")
     check_build_out("hello, world", s)
 
 
 # two arguments, and `--`
+@dotnet.xdist_group_if_macos
 def test_two_args_dash_dash(codeql, csharp):
     s = codeql.database.create(command="dotnet run -- hello world", _capture="stdout")
     check_build_out("hello, world", s)
@@ -42,6 +50,7 @@ def test_two_args_dash_dash(codeql, csharp):
 
 # shared compilation enabled; tracer should override by changing the command
 # to `dotnet run -p:UseSharedCompilation=true -p:UseSharedCompilation=false -- hello world`
+@dotnet.xdist_group_if_macos
 def test_shared_compilation(codeql, csharp):
     s = codeql.database.create(
         command="dotnet run -p:UseSharedCompilation=true -- hello world", _capture="stdout"
@@ -50,6 +59,7 @@ def test_shared_compilation(codeql, csharp):
 
 
 # option passed into `dotnet run`
+@dotnet.xdist_group_if_macos
 def test_option(codeql, csharp):
     s = codeql.database.create(
         command=["dotnet build", "dotnet run --no-build hello world"], _capture="stdout"
@@ -58,12 +68,14 @@ def test_option(codeql, csharp):
 
 
 # two arguments, no '--' (first argument quoted)
+@dotnet.xdist_group_if_macos
 def test_two_args_no_dash_dash_quote_first(codeql, csharp):
     s = codeql.database.create(command='dotnet run "hello world" part2', _capture="stdout")
     check_build_out("hello world, part2", s)
 
 
 # two arguments, no '--' (second argument quoted) and using dotnet to execute dotnet
+@dotnet.xdist_group_if_macos
 def test_two_args_no_dash_dash_quote_second(codeql, csharp):
     s = codeql.database.create(command='dotnet dotnet run hello "world part2"', _capture="stdout")
     check_build_out("hello, world part2", s)
diff --git a/csharp/ql/integration-tests/all-platforms/msbuild/test.py b/csharp/ql/integration-tests/all-platforms/msbuild/test.py
index d93379073354..61153cd327f5 100644
--- a/csharp/ql/integration-tests/all-platforms/msbuild/test.py
+++ b/csharp/ql/integration-tests/all-platforms/msbuild/test.py
@@ -1,3 +1,6 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     # force CodeQL to use MSBuild by setting `LGTM_INDEX_MSBUILD_TARGET`
     codeql.database.create(_env={"LGTM_INDEX_MSBUILD_TARGET": "Build"})
diff --git a/csharp/ql/integration-tests/all-platforms/source_generator/test.py b/csharp/ql/integration-tests/all-platforms/source_generator/test.py
index 7085307904f9..ec19d6061049 100644
--- a/csharp/ql/integration-tests/all-platforms/source_generator/test.py
+++ b/csharp/ql/integration-tests/all-platforms/source_generator/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(command="dotnet build")
diff --git a/csharp/ql/integration-tests/all-platforms/standalone/test.py b/csharp/ql/integration-tests/all-platforms/standalone/test.py
index f93a36594c8b..747ee1b636f2 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     os.environ["CODEQL_EXTRACTOR_CSHARP_OPTION_COMPILER_DIAGNOSTIC_LIMIT"] = "2"
     os.environ["CODEQL_EXTRACTOR_CSHARP_OPTION_MESSAGE_LIMIT"] = "5"
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_buildless_option/test.py b/csharp/ql/integration-tests/all-platforms/standalone_buildless_option/test.py
index 9a17ccf3b59a..b5294879f5cf 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_buildless_option/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_buildless_option/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     os.environ["CODEQL_EXTRACTOR_CSHARP_OPTION_BUILDLESS"] = "true"
     codeql.database.create()
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_dependencies_net48/test.py b/csharp/ql/integration-tests/all-platforms/standalone_dependencies_net48/test.py
index 237174a46c6b..5ce95a5c8b53 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_dependencies_net48/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_dependencies_net48/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_dependency_dir/test.py b/csharp/ql/integration-tests/all-platforms/standalone_dependency_dir/test.py
index 3629693ad29e..053bcd994829 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_dependency_dir/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_dependency_dir/test.py
@@ -1,6 +1,8 @@
 import os
 import shutil
+import dotnet
 
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp, cwd):
     path = os.path.join(cwd, "dependencies")
     os.environ["CODEQL_EXTRACTOR_CSHARP_OPTION_BUILDLESS_DEPENDENCY_DIR"] = path
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_failed/test.py b/csharp/ql/integration-tests/all-platforms/standalone_failed/test.py
index 2d8beed3deba..b65cc177d402 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_failed/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_failed/test.py
@@ -1,2 +1,5 @@
+import dotnet
+
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none", _assert_failure=True)
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_resx/test.py b/csharp/ql/integration-tests/all-platforms/standalone_resx/test.py
index d799c830dd94..64e53053ecf4 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_resx/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_resx/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     # Making sure the reachability test of `nuget.org` succeeds:
     os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_NUGET_FEEDS_CHECK_FALLBACK_TIMEOUT"] = "1000"
diff --git a/csharp/ql/integration-tests/all-platforms/standalone_winforms/test.py b/csharp/ql/integration-tests/all-platforms/standalone_winforms/test.py
index c4f98dd36290..cad710867f7c 100644
--- a/csharp/ql/integration-tests/all-platforms/standalone_winforms/test.py
+++ b/csharp/ql/integration-tests/all-platforms/standalone_winforms/test.py
@@ -1,6 +1,7 @@
 import os
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     # Making sure the reachability test of `nuget.org` succeeds:
     os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_NUGET_FEEDS_CHECK_FALLBACK_TIMEOUT"] = "1000"
diff --git a/csharp/ql/integration-tests/posix/diag_autobuild_script/test.py b/csharp/ql/integration-tests/posix/diag_autobuild_script/test.py
index f6a940c18c11..eadd73a1e4eb 100644
--- a/csharp/ql/integration-tests/posix/diag_autobuild_script/test.py
+++ b/csharp/ql/integration-tests/posix/diag_autobuild_script/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(_assert_failure=True)
diff --git a/csharp/ql/integration-tests/posix/diag_multiple_scripts/test.py b/csharp/ql/integration-tests/posix/diag_multiple_scripts/test.py
index f6a940c18c11..eadd73a1e4eb 100644
--- a/csharp/ql/integration-tests/posix/diag_multiple_scripts/test.py
+++ b/csharp/ql/integration-tests/posix/diag_multiple_scripts/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(_assert_failure=True)
diff --git a/csharp/ql/integration-tests/posix/dotnet_test/test.py b/csharp/ql/integration-tests/posix/dotnet_test/test.py
index 6417f6a17971..6deee83261cf 100644
--- a/csharp/ql/integration-tests/posix/dotnet_test/test.py
+++ b/csharp/ql/integration-tests/posix/dotnet_test/test.py
@@ -1,17 +1,20 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_implicit_build_then_run(codeql, csharp):
     codeql.database.create(command="dotnet test")
 
 
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_explicit_build_then_run(codeql, csharp):
     codeql.database.create(command=["dotnet build -o myout", "dotnet test myout/dotnet_test.dll"])
 
 
 # Explicit build and then run tests using the absolute path.
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_explicit_build_then_run_abs_path(codeql, csharp, cwd):
     codeql.database.create(
diff --git a/csharp/ql/integration-tests/posix/dotnet_test_mstest/test.py b/csharp/ql/integration-tests/posix/dotnet_test_mstest/test.py
index e59a23edb600..a941ffb0a4d5 100644
--- a/csharp/ql/integration-tests/posix/dotnet_test_mstest/test.py
+++ b/csharp/ql/integration-tests/posix/dotnet_test_mstest/test.py
@@ -1,12 +1,14 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_implicit_build_and_test(codeql, csharp):
     codeql.database.create(command="dotnet test")
 
 
 # Explicitly build and then run tests.
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_explicit_build_and_test(codeql, csharp):
     # Fix `dotnet test` picking `x64` on arm-based macOS
diff --git a/csharp/ql/integration-tests/posix/inherit-env-vars/test.py b/csharp/ql/integration-tests/posix/inherit-env-vars/test.py
index 31e31c8565d4..82443dc01a55 100644
--- a/csharp/ql/integration-tests/posix/inherit-env-vars/test.py
+++ b/csharp/ql/integration-tests/posix/inherit-env-vars/test.py
@@ -1,7 +1,8 @@
 import os
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     os.environ["PROJECT_TO_BUILD"] = "proj.csproj.no_auto"
diff --git a/csharp/ql/integration-tests/posix/query-suite/test.py b/csharp/ql/integration-tests/posix/query-suite/test.py
index 0bc7182bc086..2a2e609f7988 100644
--- a/csharp/ql/integration-tests/posix/query-suite/test.py
+++ b/csharp/ql/integration-tests/posix/query-suite/test.py
@@ -1,14 +1,17 @@
 import runs_on
 import pytest
+import dotnet
 from query_suites import *
 
 well_known_query_suites = ['csharp-code-quality.qls', 'csharp-code-quality-extended.qls', 'csharp-security-and-quality.qls', 'csharp-security-extended.qls', 'csharp-code-scanning.qls']
 
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 @pytest.mark.parametrize("query_suite", well_known_query_suites)
 def test(codeql, csharp, check_query_suite, query_suite):
     check_query_suite(query_suite)
 
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test_not_included_queries(codeql, csharp, check_queries_not_included):
     check_queries_not_included('csharp', well_known_query_suites)
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies/test.py
index 5aaafca6a46a..d31799935963 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_executing_runtime/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_executing_runtime/test.py
index 5aaafca6a46a..d31799935963 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_executing_runtime/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_executing_runtime/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_multi_project/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_multi_project/test.py
index 5aaafca6a46a..d31799935963 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_multi_project/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_multi_project/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_multi_target/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_multi_target/test.py
index 5aaafca6a46a..d31799935963 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_multi_target/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_multi_target/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_no_framework/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_no_framework/test.py
index d1c1745d69b6..8cdb38080515 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_no_framework/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_no_framework/test.py
@@ -1,13 +1,14 @@
 import runs_on
 import pytest
 import os
-
+import dotnet
 
 # Skipping the test on the ARM runners and macos-15, as we're running into trouble with Mono and nuget.
 @pytest.mark.only_if(
     runs_on.linux
     or (runs_on.macos and runs_on.x86_64 and not runs_on.macos_15)
 )
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_DOTNET_FRAMEWORK_REFERENCES"] = (
         "/non-existent-path"
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget with_space/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget with_space/test.py
index 6d2058c684c2..b76ea6628435 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget with_space/test.py	
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget with_space/test.py	
@@ -1,13 +1,14 @@
 import os
 import runs_on
 import pytest
-
+import dotnet
 
 # Skipping the test on the ARM runners and macos-15, as we're running into trouble with Mono and nuget.
 @pytest.mark.only_if(
     runs_on.linux
     or (runs_on.macos and runs_on.x86_64 and not runs_on.macos_15)
 )
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     # making sure we're not doing any fallback restore:
     os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_NUGET_FEEDS_CHECK_FALLBACK_TIMEOUT"] = "1"
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget/test.py
index 7f88196097ff..d514ff44f2e3 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget/test.py
@@ -1,11 +1,12 @@
 import runs_on
 import pytest
-
+import dotnet
 
 # Skipping the test on the ARM runners and macos-15, as we're running into trouble with Mono and nuget.
 @pytest.mark.only_if(
     runs_on.linux
     or (runs_on.macos and runs_on.x86_64 and not runs_on.macos_15)
 )
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error/test.py
index 42405ca54d4e..a758fdaa1301 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error/test.py
@@ -1,7 +1,8 @@
 import os
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     # Making sure the reachability test of `nuget.org` succeeds:
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error_timeout/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error_timeout/test.py
index 9dcc8952b173..5fe704bdccf7 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error_timeout/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_error_timeout/test.py
@@ -1,7 +1,8 @@
 import os
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     # os.environ["CODEQL_EXTRACTOR_CSHARP_BUILDLESS_NUGET_FEEDS_CHECK"] = "true"        # NuGet feed check is enabled by default
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_fallback/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_fallback/test.py
index 56bd28a23291..e333e81e2be7 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_fallback/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_config_fallback/test.py
@@ -1,7 +1,8 @@
 import os
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
 
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_no_sources/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_no_sources/test.py
index 185fb5201f95..76a036c07753 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_no_sources/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_no_sources/test.py
@@ -1,11 +1,12 @@
 import runs_on
 import pytest
-
+import dotnet
 
 # Skipping the test on the ARM runners, as we're running into trouble with Mono and nuget.
 @pytest.mark.only_if(
     runs_on.linux
     or (runs_on.macos and runs_on.x86_64 and not runs_on.macos_15)
 )
+@dotnet.xdist_group_if_macos
 def test(codeql, csharp):
     codeql.database.create(source_root="proj", build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_versions/test.py b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_versions/test.py
index 5aaafca6a46a..d31799935963 100644
--- a/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_versions/test.py
+++ b/csharp/ql/integration-tests/posix/standalone_dependencies_nuget_versions/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(build_mode="none")
diff --git a/csharp/ql/integration-tests/posix/warn_as_error/test.py b/csharp/ql/integration-tests/posix/warn_as_error/test.py
index 1b7bbd051235..c876a946915c 100644
--- a/csharp/ql/integration-tests/posix/warn_as_error/test.py
+++ b/csharp/ql/integration-tests/posix/warn_as_error/test.py
@@ -1,6 +1,7 @@
 import runs_on
+import dotnet
 
-
+@dotnet.xdist_group_if_macos
 @runs_on.posix
 def test(codeql, csharp):
     codeql.database.create(command="./build.sh")