diff --git a/oslo_log/formatters.py b/oslo_log/formatters.py
index eaf83e68..9277856c 100644
--- a/oslo_log/formatters.py
+++ b/oslo_log/formatters.py
@@ -156,6 +156,13 @@ def _get_error_summary(record):
                 exc_info[0],
                 exc_info[1],
             )[0].rstrip()
+            # If the exc_info wasn't explicitly passed to us, take only the
+            # first line of it. _Remote exceptions from oslo.messaging append
+            # the full traceback to the exception message, so we want to avoid
+            # outputting the traceback unless we've been passed exc_info
+            # directly (via LOG.exception(), for example).
+            if not record.exc_info:
+                error_summary = error_summary.split('\n', 1)[0]
         except TypeError as type_err:
             # Work around https://bugs.python.org/issue28603
             error_summary = "<exception with %s>" % six.text_type(type_err)
diff --git a/oslo_log/tests/unit/test_log.py b/oslo_log/tests/unit/test_log.py
index b656d8f9..c8270577 100644
--- a/oslo_log/tests/unit/test_log.py
+++ b/oslo_log/tests/unit/test_log.py
@@ -541,6 +541,30 @@ class JSONFormatterTestCase(LogTestBase):
         self.assertIn('error_summary', data)
         self.assertEqual('', data['error_summary'])
 
+    def test_exception_without_exc_info_passed(self):
+        ctxt = _fake_context()
+        ctxt.request_id = six.text_type('99')
+        try:
+            raise RuntimeError('test_exception\ntraceback\nfrom\nremote error')
+        except RuntimeError:
+            self.log.warning('testing', context=ctxt)
+        data = jsonutils.loads(self.stream.getvalue())
+        self.assertIn('error_summary', data)
+        self.assertEqual('RuntimeError: test_exception', data['error_summary'])
+
+    def test_exception_with_exc_info_passed(self):
+        ctxt = _fake_context()
+        ctxt.request_id = six.text_type('99')
+        try:
+            raise RuntimeError('test_exception\ntraceback\nfrom\nremote error')
+        except RuntimeError:
+            self.log.exception('testing', context=ctxt)
+        data = jsonutils.loads(self.stream.getvalue())
+        self.assertIn('error_summary', data)
+        self.assertEqual('RuntimeError: test_exception'
+                         '\ntraceback\nfrom\nremote error',
+                         data['error_summary'])
+
     def test_fallback(self):
         if not formatters._HAVE_JSONUTILS_FALLBACK:
             self.skipTest("need the fallback parameter of "