diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
index 65d030ed9afe..1d1aa519aad6 100644
--- a/lib/matplotlib/testing/decorators.py
+++ b/lib/matplotlib/testing/decorators.py
@@ -8,6 +8,7 @@
 import sys
 import unittest
 import warnings
+import string
 
 import matplotlib as mpl
 import matplotlib.style
@@ -17,7 +18,7 @@
 from matplotlib import ft2font
 from matplotlib import pyplot as plt
 from matplotlib import ticker
-from . import is_called_from_pytest
+
 from .compare import comparable_formats, compare_images, make_test_filename
 from .exceptions import ImageComparisonFailure
 
@@ -381,22 +382,23 @@ def test_plot(fig_test, fig_ref):
             fig_test.subplots().plot([1, 3, 5])
             fig_ref.subplots().plot([0, 1, 2], [1, 3, 5])
     """
-    POSITIONAL_OR_KEYWORD = inspect.Parameter.POSITIONAL_OR_KEYWORD
+    ALLOWED_CHARS = set(string.digits + string.ascii_letters + '_-[]()')
+    KEYWORD_ONLY = inspect.Parameter.KEYWORD_ONLY
     def decorator(func):
         import pytest
 
         _, result_dir = _image_directories(func)
 
         @pytest.mark.parametrize("ext", extensions)
-        def wrapper(*args, ext, **kwargs):
+        def wrapper(*args, ext, request, **kwargs):
+            file_name = "".join(c for c in request.node.name
+                                if c in ALLOWED_CHARS)
             try:
                 fig_test = plt.figure("test")
                 fig_ref = plt.figure("reference")
                 func(*args, fig_test=fig_test, fig_ref=fig_ref, **kwargs)
-                test_image_path = result_dir / (func.__name__ + "." + ext)
-                ref_image_path = result_dir / (
-                    func.__name__ + "-expected." + ext
-                )
+                test_image_path = result_dir / (file_name + "." + ext)
+                ref_image_path = result_dir / (file_name + "-expected." + ext)
                 fig_test.savefig(test_image_path)
                 fig_ref.savefig(ref_image_path)
                 _raise_on_image_difference(
@@ -411,7 +413,10 @@ def wrapper(*args, ext, **kwargs):
             parameters=([param
                          for param in sig.parameters.values()
                          if param.name not in {"fig_test", "fig_ref"}]
-                        + [inspect.Parameter("ext", POSITIONAL_OR_KEYWORD)])
+                        + [
+                            inspect.Parameter("ext", KEYWORD_ONLY),
+                            inspect.Parameter("request", KEYWORD_ONLY),
+                        ])
         )
         wrapper.__signature__ = new_sig