diff --git a/pyproject.toml b/pyproject.toml
index 7ee74409e..218cf93d6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,7 @@ authors = [
 dependencies = [
   "click ~= 8.1.0; python_version == '3.8'",
   "click ~= 8.1.0; python_version == '3.9'",
-  "click >= 8.1.0, < 8.5.0; python_version >= '3.10'",
+  "click >= 8.1.0, < 8.6.0; python_version >= '3.10'",
   "click-option-group ~= 0.5.0",
   "gitpython ~= 3.0",
   "requests ~= 2.25",
@@ -75,7 +75,7 @@ docs = [
 test = [
   "coverage[toml] ~= 7.0",
   "filelock ~= 3.15",
-  "flatdict ~= 4.0",
+  "cj365-flatdict ~= 5.0",
   "freezegun ~= 1.5",
   "pyyaml ~= 6.0",
   "pytest >= 8.3, < 10.0",
@@ -208,10 +208,6 @@ plugins = ["pydantic.mypy"]
 module = "tests.*"
 disallow_untyped_defs = false
 
-[[tool.mypy.overrides]]
-module = "flatdict"
-ignore_missing_imports = true
-
 [[tool.mypy.overrides]]
 module = "shellingham"
 ignore_missing_imports = true
diff --git a/tests/e2e/cmd_version/test_version_build.py b/tests/e2e/cmd_version/test_version_build.py
index 068377543..13bfd6627 100644
--- a/tests/e2e/cmd_version/test_version_build.py
+++ b/tests/e2e/cmd_version/test_version_build.py
@@ -10,7 +10,7 @@
 import pytest
 import shellingham
 import tomlkit
-from flatdict import FlatDict
+from cj365.flatdict import FlatDict
 from pytest_lazy_fixtures.lazy_fixture import lf as lazy_fixture
 
 from tests.const import MAIN_PROG_NAME, VERSION_SUBCMD
diff --git a/tests/fixtures/monorepos/git_monorepo.py b/tests/fixtures/monorepos/git_monorepo.py
index 59da65df9..3dc98ab92 100644
--- a/tests/fixtures/monorepos/git_monorepo.py
+++ b/tests/fixtures/monorepos/git_monorepo.py
@@ -84,7 +84,8 @@ def cached_example_git_monorepo(
 
     def _build_repo(cached_repo_path: Path) -> Sequence[RepoActions]:
         if not cached_example_monorepo.exists():
-            raise RuntimeError("Unable to find cached monorepo files")
+            msg = "Unable to find cached monorepo files"
+            raise RuntimeError(msg)
 
         # make a copy of the example monorepo as a base
         copy_dir_tree(cached_example_monorepo, cached_repo_path)
@@ -109,6 +110,11 @@ def _build_repo(cached_repo_path: Path) -> Sequence[RepoActions]:
                 config.set_value("commit", "gpgsign", False)
                 config.set_value("tag", "gpgsign", False)
 
+                # Disable automatic garbage collection and background maintenance to prevent race conditions
+                config.set_value("gc", "auto", 0)
+                config.set_value("gc", "autoDetach", "false")
+                config.set_value("maintenance", "auto", "false")
+
                 # set up a remote tracking branch for the default branch
                 config.set_value(f'branch "{DEFAULT_BRANCH_NAME}"', "remote", "origin")
                 config.set_value(