diff --git a/changelogs/fragments/ansible-test-diff-prefix-optional.yml b/changelogs/fragments/ansible-test-diff-prefix-optional.yml
new file mode 100644
index 00000000000..2394965328d
--- /dev/null
+++ b/changelogs/fragments/ansible-test-diff-prefix-optional.yml
@@ -0,0 +1,4 @@
+bugfixes:
+  - >-
+    ansible-test - make the ``a/`` and ``b/`` prefixes an optional match
+    since these can be turned off with the ``diff.noprefix`` setting in ``git``
diff --git a/test/lib/ansible_test/_internal/diff.py b/test/lib/ansible_test/_internal/diff.py
index 1e2038b98be..5671ec7f280 100644
--- a/test/lib/ansible_test/_internal/diff.py
+++ b/test/lib/ansible_test/_internal/diff.py
@@ -180,7 +180,7 @@ class DiffParser:
         """Process a diff start line."""
         self.complete_file()
 
-        match = re.search(r'^diff --git "?a/(?P<old_path>.*)"? "?b/(?P<new_path>.*)"?$', self.line)
+        match = re.search(r'^diff --git "?(?:a/)?(?P<old_path>.*)"? "?(?:b/)?(?P<new_path>.*)"?$', self.line)
 
         if not match:
             raise Exception('Unexpected diff start line.')