diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index e98a99aa85b..0c01cd2beac 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -598,6 +598,10 @@ def runtest_inner(test, generate, verbose, quiet, test_times,
     refleak = False  # True if the test leaked references.
     try:
         save_stdout = sys.stdout
+        # Save various things that tests may mess up so we can restore
+        # them afterward.
+        save_environ = dict(os.environ)
+        save_argv = sys.argv[:]
         try:
             if cfp:
                 sys.stdout = cfp
@@ -622,6 +626,17 @@ def runtest_inner(test, generate, verbose, quiet, test_times,
             test_times.append((test_time, test))
         finally:
             sys.stdout = save_stdout
+            # Restore what we saved if needed, but also complain if the test
+            # changed it so that the test may eventually get fixed.
+            if not os.environ == save_environ:
+                if not quiet:
+                    print("Warning: os.environ was modified by", test)
+                os.environ.clear()
+                os.environ.update(save_environ)
+            if not sys.argv == save_argv:
+                if not quiet:
+                    print("Warning: argv was modified by", test)
+                sys.argv[:] = save_argv
     except support.ResourceDenied as msg:
         if not quiet:
             print(test, "skipped --", msg)
diff --git a/Misc/NEWS b/Misc/NEWS
index 4b6ff0b514d..96ad164caf6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -79,6 +79,9 @@ Extension Modules
 Tests
 -----
 
+- Issue #7058: Added save/restore for argv and os.environ to runtest_inner
+  in regrtest, with warnings if the called test modifies them.
+
 - Issue #7042: Fix test_signal (test_itimer_virtual) failure on OS X 10.6.
 
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