diff --git a/t/fixtures/programs.py b/t/fixtures/programs.py
index 22511487..ccd69e9b 100644
--- a/t/fixtures/programs.py
+++ b/t/fixtures/programs.py
@@ -1,5 +1,5 @@
 import pytest
-from os import getuid
+from os import chown, getuid, getgid
 from pathlib import Path
 import subprocess
 import sys
@@ -147,6 +147,14 @@ def process_pool(env, cfg, git):
         src = cfg.get("ngcpcfg", key_base)
         copy_tree(src, src, dst_pool)
         cfg.set("ngcpcfg", key_base, str(dst_pool))
+
+        # ensure we have valid user information
+        git.config("--local", "user.email", "pytest@example.com")
+        git.config("--local", "user.name", "pytest")
+
+        # required for git versions >=2.35.2
+        chown(ngcpctl_dir, getuid(), getgid())
+
         ex, out, err = git.add("templates")
         assert ex == 0
         # print("{}\nstdout:\n{}stderr:{}\n".format("git add", out, err))
@@ -159,6 +167,10 @@ def process_pool(env, cfg, git):
             dir_path = Path(outdir).joinpath(dir[1:])
             print("create empty git repository at {}".format(dir_path))
             gitrepo.extract_archive(str(EMPTY_GIT), dir_path)
+            # ensure we have valid user information
+            git.config("--local", "user.email", "pytest@example.com")
+            git.config("--local", "user.name", "pytest")
+
 
     def process_conf(env, cfg, git):
         base = Path(cfg.get("ngcpcfg", "NGCPCTL_MAIN"))
@@ -199,15 +211,21 @@ def prepare_conf(env={}):
             config.set("ngcpcfg", key, str(testenv[key]))
 
         with gitrepo.in_folder(ngcpctl_dir) as git:
-            git.config("user.email", "fake@pytest.fake")
-            git.config("user.name", "pytest")
+            # ensure we have valid user information
+            git.config("--local", "user.email", "pytest@example.com")
+            git.config("--local", "user.name", "pytest")
             process_conf(testenv, config, git)
             # generate NGCPCFG with config values
             testenv["NGCPCFG"] = gen_cfg(config, ngcpctl_dir)
             git.add(testenv["NGCPCFG"])
+
             # ex, out, err = git.diff("HEAD")
             # print("{}\nstdout:\n{}stderr:{}\n".format("git diff", out, err))
             ex, out, err = git.commit("-a", "-m", "prepare_conf done")
+
+            # for debugging underlying problems like safe.directory situation
+            print("debug: git show: {}\n".format(subprocess.getoutput("git show")))
+
             print("{}\nstdout:\n{}stderr:{}\n".format("git commit", out, err))
             assert ex == 0
         return testenv, config["ngcpcfg"]
@@ -296,4 +314,4 @@ def run(helper, *args, env={}):
         )
         return result
 
-    return run
\ No newline at end of file
+    return run
diff --git a/t/test_git.py b/t/test_git.py
index 293b90d1..2e17c84e 100644
--- a/t/test_git.py
+++ b/t/test_git.py
@@ -9,9 +9,14 @@ def test_add_file_to_default_repo(cli, gitrepo):
     src = "default-git-repository.tar.gz"
 
     with gitrepo.from_archive(src) as git:
-        # configure git user
-        git.config("--local", "user.email", "me@example.com")
-        git.config("--local", "user.name", "pytest robot")
+        # required for git versions >=2.35.2
+        os.chown(git.root, os.getuid(), os.getgid())
+
+        # ensure we have valid user information
+        git.config("--local", "user.email", "pytest@example.com")
+        git.config("--local", "user.name", "pytest")
+
+        # debug information, visible only in case of errors
         print("Using git {}".format(git.version))
 
         # git status
@@ -39,6 +44,9 @@ def test_add_file_to_default_repo(cli, gitrepo):
 def test_status_output(cli, gitrepo):
     # we mock an existing repository by loading it from the default archive
     with gitrepo.from_archive(gitrepo.default) as git:
+        # required for git versions >=2.35.2
+        os.chown(git.root, os.getuid(), os.getgid())
+
         # now we work with "existing" repository with path given in git.root
         with gitrepo.in_folder(git.root) as git:
             ex, out, err = git.status()
diff --git a/t/test_ngcpcfg_apply_instances.py b/t/test_ngcpcfg_apply_instances.py
index a3ad5132..e7e4c9d3 100644
--- a/t/test_ngcpcfg_apply_instances.py
+++ b/t/test_ngcpcfg_apply_instances.py
@@ -66,8 +66,9 @@ def test_apply_instances_changes(ngcpcfg, ngcpcfgcli, tmpdir, gitrepo):
     ]
     # put expected output of build_instances
     with gitrepo.in_folder(base_git) as git:
-        git.config("user.email", "fake@pytest.fake")
-        git.config("user.name", "pytest")
+        # ensure we have valid user information
+        git.config("--local", "user.email", "pytest@example.com")
+        git.config("--local", "user.name", "pytest")
         for file, dir in orig:
             dst_path = base_path.joinpath(dir)
             dst_path.mkdir(parents=True, exist_ok=True)