diff --git a/doc/build/changelog/unreleased_14/mypy_fixes.rst b/doc/build/changelog/unreleased_14/mypy_fixes.rst
new file mode 100644
index 0000000000..32e4f14658
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/mypy_fixes.rst
@@ -0,0 +1,9 @@
+.. change::
+    :tags: bug, tests
+
+    Adjusted the test suite which tests the Mypy plugin to accommodate for
+    changes in Mypy 0.990 regarding how it handles message output, which affect
+    how sys.path is interpreted when determining if notes and errors should be
+    printed for particular files. The change broke the test suite as the files
+    within the test directory itself no longer produced messaging when run
+    under the mypy API.
diff --git a/test/ext/mypy/test_mypy_plugin_py3k.py b/test/ext/mypy/test_mypy_plugin_py3k.py
index 181a7958f3..3df758c56d 100644
--- a/test/ext/mypy/test_mypy_plugin_py3k.py
+++ b/test/ext/mypy/test_mypy_plugin_py3k.py
@@ -63,7 +63,18 @@ class MypyPluginTest(fixtures.TestBase):
                 ),
             ]
 
-            args.append(path)
+            if incremental:
+                args.append(path)
+            else:
+                # mypy as of 0.990 is more aggressively blocking messaging
+                # for paths that are in sys.path, and as pytest puts currdir,
+                # test/ etc in sys.path, just copy the source file to the
+                # tempdir we are working in so that we don't have to try to
+                # manipulate sys.path and/or guess what mypy is doing
+                filename = os.path.basename(path)
+                test_program = os.path.join(cachedir, filename)
+                shutil.copyfile(path, test_program)
+                args.append(test_program)
 
             result = api.run(args)
             return result
@@ -185,7 +196,9 @@ class MypyPluginTest(fixtures.TestBase):
         not_located = []
 
         if expected_errors:
-            eq_(result[2], 1, msg=result)
+            # mypy 0.990 changed how return codes work, so don't assume a
+            # 1 or a 0 return code here, could be either depending on if
+            # errors were generated or not
 
             print(result[0])