diff --git a/.gitignore b/.gitignore
index 385160b014..de435d109e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ pymongo.egg-info/
 *.egg
 .tox
 mongocryptd.pid
+.idea/
diff --git a/pymongo/errors.py b/pymongo/errors.py
index cf32546850..973719dbd1 100644
--- a/pymongo/errors.py
+++ b/pymongo/errors.py
@@ -100,6 +100,14 @@ class NetworkTimeout(AutoReconnect):
     """
 
 
+def _format_detailed_error(message, details):
+    if details is not None:
+        message = "%s, full error: %s" % (message, details)
+        if sys.version_info[0] == 2 and isinstance(message, unicode):
+            message = message.encode('utf-8', errors='replace')
+    return message
+
+
 class NotMasterError(AutoReconnect):
     """The server responded "not master" or "node is recovering".
 
@@ -113,11 +121,10 @@ class NotMasterError(AutoReconnect):
 
     Subclass of :exc:`~pymongo.errors.AutoReconnect`.
     """
-    def __str__(self):
-        output_str = "%s, full error: %s" % (self._message, self.__details)
-        if sys.version_info[0] == 2 and isinstance(output_str, unicode):
-            return output_str.encode('utf-8', errors='replace')
-        return output_str
+    def __init__(self, message='', errors=None):
+        super(NotMasterError, self).__init__(
+            _format_detailed_error(message, errors), errors=errors)
+
 
 class ServerSelectionTimeoutError(AutoReconnect):
     """Thrown when no MongoDB server is available for an operation
@@ -149,7 +156,7 @@ def __init__(self, error, code=None, details=None):
         if details is not None:
             error_labels = details.get('errorLabels')
         super(OperationFailure, self).__init__(
-            error, error_labels=error_labels)
+            _format_detailed_error(error, details), error_labels=error_labels)
         self.__code = code
         self.__details = details
 
@@ -171,11 +178,6 @@ def details(self):
         """
         return self.__details
 
-    def __str__(self):
-        output_str = "%s, full error: %s" % (self._message, self.__details)
-        if sys.version_info[0] == 2 and isinstance(output_str, unicode):
-            return output_str.encode('utf-8', errors='replace')
-        return output_str
 
 class CursorNotFound(OperationFailure):
     """Raised while iterating query results if the cursor is
diff --git a/test/test_database.py b/test/test_database.py
index 43fac30b0e..6feb1a84e9 100644
--- a/test/test_database.py
+++ b/test/test_database.py
@@ -959,7 +959,7 @@ def test_command_response_without_ok(self):
         try:
             helpers._check_command_response({'$err': 'foo'})
         except OperationFailure as e:
-            self.assertEqual(e.args[0], 'foo')
+            self.assertEqual(e.args[0], "foo, full error: {'$err': 'foo'}")
         else:
             self.fail("_check_command_response didn't raise OperationFailure")
 
diff --git a/test/test_errors.py b/test/test_errors.py
new file mode 100644
index 0000000000..32d7af3284
--- /dev/null
+++ b/test/test_errors.py
@@ -0,0 +1,73 @@
+# Copyright 2020-present MongoDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+import traceback
+
+sys.path[0:0] = [""]
+
+from pymongo.errors import (NotMasterError,
+                            OperationFailure)
+from test import (PyMongoTestCase,
+                  unittest)
+
+
+class TestErrors(PyMongoTestCase):
+    def test_not_master_error(self):
+        exc = NotMasterError("not master test", {"errmsg": "error"})
+        self.assertIn("full error", str(exc))
+        try:
+            raise exc
+        except NotMasterError:
+            self.assertIn("full error", traceback.format_exc())
+
+    def test_operation_failure(self):
+        exc = OperationFailure("operation failure test", 10,
+                               {"errmsg": "error"})
+        self.assertIn("full error", str(exc))
+        try:
+            raise exc
+        except OperationFailure:
+            self.assertIn("full error", traceback.format_exc())
+
+    def _test_unicode_strs(self, exc):
+        if sys.version_info[0] == 2:
+            self.assertEqual("unicode \xf0\x9f\x90\x8d, full error: {"
+                             "'errmsg': u'unicode \\U0001f40d'}", str(exc))
+        elif 'PyPy' in sys.version:
+            # PyPy displays unicode in repr differently.
+            self.assertEqual("unicode \U0001f40d, full error: {"
+                             "'errmsg': 'unicode \\U0001f40d'}", str(exc))
+        else:
+            self.assertEqual("unicode \U0001f40d, full error: {"
+                             "'errmsg': 'unicode \U0001f40d'}", str(exc))
+        try:
+            raise exc
+        except Exception:
+            self.assertIn("full error", traceback.format_exc())
+
+    def test_unicode_strs_operation_failure(self):
+        exc = OperationFailure(u'unicode \U0001f40d', 10,
+                               {"errmsg": u'unicode \U0001f40d'})
+        self._test_unicode_strs(exc)
+
+    def test_unicode_strs_not_master_error(self):
+        exc = NotMasterError(u'unicode \U0001f40d',
+                             {"errmsg": u'unicode \U0001f40d'})
+        self._test_unicode_strs(exc)
+
+
+
+if __name__ == "__main__":
+    unittest.main()