diff --git a/jupyterhub/objects.py b/jupyterhub/objects.py
index 5927a7d8..ed361f8d 100644
--- a/jupyterhub/objects.py
+++ b/jupyterhub/objects.py
@@ -219,4 +219,5 @@ class Hub(Server):
         return url_path_join(self.url, 'api')
 
     def __repr__(self):
-        return f"<{self.__class__.__name__} {self.ip}:{self.port}>"
+        ip = f"[{self.ip}]" if ":" in self.ip else self.ip
+        return f"<{self.__class__.__name__} {ip}:{self.port}>"
diff --git a/jupyterhub/orm.py b/jupyterhub/orm.py
index a08b6967..698f5219 100644
--- a/jupyterhub/orm.py
+++ b/jupyterhub/orm.py
@@ -157,7 +157,8 @@ class Server(Base):
     spawner = relationship("Spawner", back_populates="server", uselist=False)
 
     def __repr__(self):
-        return f"<Server({self.ip}:{self.port})>"
+        ip = f"[{self.ip}]" if ":" in self.ip else self.ip
+        return f"<Server({ip}:{self.port})>"
 
 
 # lots of things have roles
diff --git a/jupyterhub/utils.py b/jupyterhub/utils.py
index 6ee7de66..fc35ff4f 100644
--- a/jupyterhub/utils.py
+++ b/jupyterhub/utils.py
@@ -269,15 +269,16 @@ async def wait_for_server(ip, port, timeout=10):
     """Wait for any server to show up at ip:port."""
     if ip in {'', '0.0.0.0', '::'}:
         ip = '127.0.0.1'
-    app_log.debug("Waiting %ss for server at %s:%s", timeout, ip, port)
+    display_ip = f"[{ip}]" if ":" in ip else ip
+    app_log.debug("Waiting %ss for server at %s:%s", timeout, display_ip, port)
     tic = time.perf_counter()
     await exponential_backoff(
         lambda: can_connect(ip, port),
-        f"Server at {ip}:{port} didn't respond in {timeout} seconds",
+        f"Server at {display_ip}:{port} didn't respond in {timeout} seconds",
         timeout=timeout,
     )
     toc = time.perf_counter()
-    app_log.debug("Server at %s:%s responded in %.2fs", ip, port, toc - tic)
+    app_log.debug("Server at %s:%s responded in %.2fs", display_ip, port, toc - tic)
 
 
 async def wait_for_http_server(url, timeout=10, ssl_context=None):