--- Lib/test/libregrtest/main.py
+++ Lib/test/libregrtest/main.py
@@ -86,7 +86,7 @@
         self.next_single_filename = None
 
     def accumulate_result(self, test, result):
-        ok, test_time = result
+        ok, test_time = result[:2]
         self.test_times.append((test_time, test))
         if ok == PASSED:
             self.good.append(test)
--- Lib/test/libregrtest/runtest_mp.py
+++ Lib/test/libregrtest/runtest_mp.py
@@ -68,10 +68,10 @@
     try:
         result = runtest(ns, testname)
     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)
 
     print()   # Force a newline (just in case)
     print(json.dumps(result), flush=True)
@@ -124,7 +124,7 @@
 
         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)
             self.output.put((test, stdout.rstrip(), stderr.rstrip(),
                              result))
             return True
@@ -208,7 +208,7 @@
             if result[0] == INTERRUPTED:
                 raise KeyboardInterrupt
             if result[0] == CHILD_ERROR:
-                msg = "Child error on {}: {}".format(test, result[1])
+                msg = "Child error on {}: {}".format(test, result[2])
                 raise Exception(msg)
             test_index += 1
     except KeyboardInterrupt: