diff --git a/testing/util.py b/testing/util.py
index 2bbbe644..75a81b40 100644
--- a/testing/util.py
+++ b/testing/util.py
@@ -14,3 +14,8 @@ def get_resource_path(path):
 def git_commit(*args, **kwargs):
     cmd = ('git', 'commit', '--no-gpg-sign', '--no-verify', '--no-edit', *args)
     subprocess.check_call(cmd, **kwargs)
+
+
+def get_default_branch():
+    ret = subprocess.getoutput('git config init.defaultBranch').strip()
+    return ret or 'master'
diff --git a/tests/check_merge_conflict_test.py b/tests/check_merge_conflict_test.py
index 76c4283c..dabe3db4 100644
--- a/tests/check_merge_conflict_test.py
+++ b/tests/check_merge_conflict_test.py
@@ -7,10 +7,14 @@
 
 from pre_commit_hooks.check_merge_conflict import main
 from pre_commit_hooks.util import cmd_output
+from testing.util import get_default_branch
 from testing.util import get_resource_path
 from testing.util import git_commit
 
 
+default_branch = get_default_branch()
+
+
 @pytest.fixture
 def f1_is_a_conflict_file(tmpdir):
     # Make a merge conflict
@@ -150,7 +154,12 @@ def test_worktree_merge_conflicts(f1_is_a_conflict_file, tmpdir, capsys):
     cmd_output('git', 'worktree', 'add', str(worktree))
     with worktree.as_cwd():
         cmd_output(
-            'git', 'pull', '--no-rebase', 'origin', 'master', retcode=None,
+            'git',
+            'pull',
+            '--no-rebase',
+            'origin',
+            default_branch,
+            retcode=None,
         )
         msg = f1_is_a_conflict_file.join('.git/worktrees/worktree/MERGE_MSG')
         assert msg.exists()
diff --git a/tests/no_commit_to_branch_test.py b/tests/no_commit_to_branch_test.py
index eaae5e62..4c8207ec 100644
--- a/tests/no_commit_to_branch_test.py
+++ b/tests/no_commit_to_branch_test.py
@@ -5,19 +5,23 @@
 from pre_commit_hooks.no_commit_to_branch import is_on_branch
 from pre_commit_hooks.no_commit_to_branch import main
 from pre_commit_hooks.util import cmd_output
+from testing.util import get_default_branch
 from testing.util import git_commit
 
 
+default_branch = get_default_branch()
+
+
 def test_other_branch(temp_git_dir):
     with temp_git_dir.as_cwd():
         cmd_output('git', 'checkout', '-b', 'anotherbranch')
-        assert is_on_branch({'master'}) is False
+        assert is_on_branch({default_branch}) is False
 
 
 def test_multi_branch(temp_git_dir):
     with temp_git_dir.as_cwd():
         cmd_output('git', 'checkout', '-b', 'another/branch')
-        assert is_on_branch({'master'}) is False
+        assert is_on_branch({default_branch}) is False
 
 
 def test_multi_branch_fail(temp_git_dir):
@@ -28,7 +32,7 @@ def test_multi_branch_fail(temp_git_dir):
 
 def test_master_branch(temp_git_dir):
     with temp_git_dir.as_cwd():
-        assert is_on_branch({'master'}) is True
+        assert is_on_branch({default_branch}) is True
 
 
 def test_main_branch_call(temp_git_dir):
@@ -50,11 +54,11 @@ def test_branch_pattern_fail(temp_git_dir):
         assert is_on_branch(set(), {'another/.*'}) is True
 
 
-@pytest.mark.parametrize('branch_name', ('master', 'another/branch'))
+@pytest.mark.parametrize('branch_name', (default_branch, 'another/branch'))
 def test_branch_pattern_multiple_branches_fail(temp_git_dir, branch_name):
     with temp_git_dir.as_cwd():
         cmd_output('git', 'checkout', '-b', branch_name)
-        assert main(('--branch', 'master', '--pattern', 'another/.*'))
+        assert main(('--branch', default_branch, '--pattern', 'another/.*'))
 
 
 def test_main_default_call(temp_git_dir):