diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 4dab0e3e16..10836f4651 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -170,6 +170,8 @@ class BaseDatabaseWrapper(object):
         self.validate_no_atomic_block()
         self._commit()
         self.set_clean()
+        # A successful commit means that the database connection works.
+        self.errors_occurred = False
 
     def rollback(self):
         """
@@ -179,6 +181,8 @@ class BaseDatabaseWrapper(object):
         self.validate_no_atomic_block()
         self._rollback()
         self.set_clean()
+        # A successful rollback means that the database connection works.
+        self.errors_occurred = False
 
     def close(self):
         """
@@ -475,6 +479,8 @@ class BaseDatabaseWrapper(object):
                 self.close()
                 return
 
+            # If an exception other than DataError or IntegrityError occurred
+            # since the last commit / rollback, check if the connection works.
             if self.errors_occurred:
                 if self.is_usable():
                     self.errors_occurred = False