--- Lib/test/regrtest.py
+++ Lib/test/regrtest.py
@@ -531,10 +531,10 @@
         try:
             result = runtest(*args, **kwargs)
         except KeyboardInterrupt:
-            result = INTERRUPTED, ''
+            result = INTERRUPTED, 0.0
         except BaseException as e:
             traceback.print_exc()
-            result = CHILD_ERROR, str(e)
+            result = CHILD_ERROR, 0.0, str(e)
         sys.stdout.flush()
         print()   # Force a newline (just in case)
         print(json.dumps(result))
@@ -644,7 +644,7 @@
     save_modules = sys.modules.keys()
 
     def accumulate_result(test, result):
-        ok, test_time = result
+        ok, test_time = result[:2]
         test_times.append((test_time, test))
         if ok == PASSED:
             good.append(test)
@@ -698,7 +698,7 @@
                     stderr = debug_output_pat.sub("", stderr)
                     stdout, _, result = stdout.strip().rpartition("\n")
                     if retcode != 0:
-                        result = (CHILD_ERROR, "Exit code %s" % retcode)
+                        result = (CHILD_ERROR, 0.0, "Exit code %s" % retcode)
                         output.put((test, stdout.rstrip(), stderr.rstrip(), result))
                         return
                     if not result:
@@ -735,7 +735,7 @@
                 if result[0] == INTERRUPTED:
                     raise KeyboardInterrupt
                 if result[0] == CHILD_ERROR:
-                    raise Exception("Child error on {}: {}".format(test, result[1]))
+                    raise Exception("Child error on {}: {}".format(test, result[2]))
                 test_index += 1
         except KeyboardInterrupt:
             interrupted = True