diff --git a/tests/file_storage/test_generate_filename.py b/tests/file_storage/test_generate_filename.py
index 66551c495b..cb64650920 100644
--- a/tests/file_storage/test_generate_filename.py
+++ b/tests/file_storage/test_generate_filename.py
@@ -71,7 +71,7 @@ class GenerateFilenameStorageTests(SimpleTestCase):
         ]
         f = FileField(upload_to='some/folder/')
         for file_name, msg_file_name in candidates:
-            msg = f"Could not derive file name from '{msg_file_name}'"
+            msg = "Could not derive file name from '%s'" % msg_file_name
             with self.subTest(file_name=file_name):
                 with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                     f.generate_filename(None, file_name)
@@ -89,7 +89,7 @@ class GenerateFilenameStorageTests(SimpleTestCase):
             '/tmp/../path',
         ]
         for file_name in candidates:
-            msg = f"Detected path traversal attempt in '{file_name}'"
+            msg = "Detected path traversal attempt in '%s'" % file_name
             with self.subTest(file_name=file_name):
                 with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                     f.generate_filename(None, file_name)
@@ -145,7 +145,7 @@ class GenerateFilenameStorageTests(SimpleTestCase):
             '$.$.$',
         ]
         for file_name in candidates:
-            msg = f"Detected path traversal attempt in '/tmp/{file_name}'"
+            msg = "Detected path traversal attempt in '/tmp/%s'" % file_name
             with self.subTest(file_name=file_name):
                 with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                     f.generate_filename(None, file_name)
@@ -157,7 +157,7 @@ class GenerateFilenameStorageTests(SimpleTestCase):
         f = FileField(upload_to=upload_to)
         candidates = ['..', '.', '']
         for file_name in candidates:
-            msg = f"Could not derive file name from '/tmp/{file_name}'"
+            msg = "Could not derive file name from '/tmp/%s'" % file_name
             with self.subTest(file_name=file_name):
                 with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                     f.generate_filename(None, file_name)
diff --git a/tests/model_fields/test_filefield.py b/tests/model_fields/test_filefield.py
index 2c99c34957..0afef7284e 100644
--- a/tests/model_fields/test_filefield.py
+++ b/tests/model_fields/test_filefield.py
@@ -66,7 +66,7 @@ class FileFieldTests(TestCase):
         with tempfile.NamedTemporaryFile(suffix='.txt') as tmp:
             document = Document.objects.create(myfile='something.txt')
             document.myfile = File(tmp)
-            msg = f"Detected path traversal attempt in '{tmp.name}'"
+            msg = "Detected path traversal attempt in '%s'" % tmp.name
             with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                 document.save()