diff --git a/python/mozbuild/mozbuild/artifacts.py b/python/mozbuild/mozbuild/artifacts.py
index 6848f0da8ed6..ac99ad007702 100644
--- a/python/mozbuild/mozbuild/artifacts.py
+++ b/python/mozbuild/mozbuild/artifacts.py
@@ -233,6 +233,15 @@ class ArtifactJob(object):
                     writer.add(destpath.encode('utf-8'), reader[filename], mode=mode)
                     added_entry = True
                     break
+
+                if filename.endswith('.ini'):
+                    # The artifact build writes test .ini files into the object
+                    # directory; they don't come from the upstream test archive.
+                    self.log(logging.INFO, 'artifact',
+                             {'filename': filename},
+                             'Skipping test INI file {filename}')
+                    continue
+
                 for files_entry in OBJDIR_TEST_FILES.values():
                     origin_pattern = files_entry['pattern']
                     leaf_filename = filename
@@ -270,6 +279,15 @@ class ArtifactJob(object):
                         writer.add(destpath.encode('utf-8'), entry.open(), mode=mode)
                         added_entry = True
                         break
+
+                    if filename.endswith('.ini'):
+                        # The artifact build writes test .ini files into the object
+                        # directory; they don't come from the upstream test archive.
+                        self.log(logging.INFO, 'artifact',
+                                 {'filename': filename},
+                                 'Skipping test INI file {filename}')
+                        continue
+
                     for files_entry in OBJDIR_TEST_FILES.values():
                         origin_pattern = files_entry['pattern']
                         leaf_filename = filename