diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index 111317b..ce7468e 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -183,7 +183,8 @@ def _exc_info_to_string(self, err, test):
         else:
             length = None
         tb_e = traceback.TracebackException(
-            exctype, value, tb, limit=length, capture_locals=self.tb_locals)
+            exctype, value, tb,
+            limit=length, capture_locals=self.tb_locals, compact=True)
         msgLines = list(tb_e.format())
 
         if self.buffer:
diff --git a/Misc/NEWS.d/next/Library/2021-01-15-11-48-00.bpo-42934.ILKoOI.rst b/Misc/NEWS.d/next/Library/2021-01-15-11-48-00.bpo-42934.ILKoOI.rst
new file mode 100644
index 0000000..92f2402
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-01-15-11-48-00.bpo-42934.ILKoOI.rst
@@ -0,0 +1,3 @@
+Use :class:`~traceback.TracebackException`'s new ``compact`` param in
+:class:`~unittest.TestResult` to reduce time and memory consumed by
+traceback formatting.