diff --git a/django/test/testcases.py b/django/test/testcases.py
index 85ff66a..6980fa2 100644
--- a/django/test/testcases.py
+++ b/django/test/testcases.py
@@ -1112,6 +1112,12 @@ class LiveServerThread(threading.Thread):
             self.error = e
             self.is_ready.set()
 
+        if not self.connections_override:
+            # This thread has its own connections which will not get closed
+            # during testcase teardown.
+            for conn in connections.all():
+                conn.close()
+
     def join(self, timeout=None):
         if hasattr(self, 'httpd'):
             # Stop the WSGI server