diff --git a/tests/trainer/test_trainer.py b/tests/trainer/test_trainer.py
index 21d8577366d28..38112e1b6be23 100644
--- a/tests/trainer/test_trainer.py
+++ b/tests/trainer/test_trainer.py
@@ -249,7 +249,7 @@ def test_dp_output_reduce():
     assert reduced['b']['c'] == out['b']['c']
 
 
-def test_model_checkpoint_options(tmp_path):
+def test_model_checkpoint_options(tmpdir):
     """Test ModelCheckpoint options."""
     def mock_save_function(filepath):
         open(filepath, 'a').close()
@@ -258,8 +258,8 @@ def mock_save_function(filepath):
     _ = LightningTestModel(hparams)
 
     # simulated losses
-    save_dir = tmp_path / "1"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '1')
+    os.mkdir(save_dir)
     losses = [10, 9, 2.8, 5, 2.5]
 
     # -----------------
@@ -286,8 +286,8 @@ def mock_save_function(filepath):
                   'epoch=0.ckpt'}:
         assert fname in file_lists
 
-    save_dir = tmp_path / "2"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '2')
+    os.mkdir(save_dir)
 
     # -----------------
     # CASE K=0 (none)
@@ -305,8 +305,8 @@ def mock_save_function(filepath):
 
     assert len(file_lists) == 0, "Should save 0 models when save_top_k=0"
 
-    save_dir = tmp_path / "3"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '3')
+    os.mkdir(save_dir)
 
     # -----------------
     # CASE K=1 (2.5, epoch 4)
@@ -325,8 +325,8 @@ def mock_save_function(filepath):
     assert len(file_lists) == 1, "Should save 1 model when save_top_k=1"
     assert 'test_prefix_epoch=4.ckpt' in file_lists
 
-    save_dir = tmp_path / "4"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '4')
+    os.mkdir(save_dir)
 
     # -----------------
     # CASE K=2 (2.5 epoch 4, 2.8 epoch 2)
@@ -351,8 +351,8 @@ def mock_save_function(filepath):
                   'other_file.ckpt'}:
         assert fname in file_lists
 
-    save_dir = tmp_path / "5"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '5')
+    os.mkdir(save_dir)
 
     # -----------------
     # CASE K=4 (save all 4 models)
@@ -372,8 +372,8 @@ def mock_save_function(filepath):
 
     assert len(file_lists) == 4, 'Should save all 4 models when save_top_k=4 within same epoch'
 
-    save_dir = tmp_path / "6"
-    save_dir.mkdir()
+    save_dir = os.path.join(tmpdir, '6')
+    os.mkdir(save_dir)
 
     # -----------------
     # CASE K=3 (save the 2nd, 3rd, 4th model)