diff --git a/stdlib/ipaddress.pyi b/stdlib/ipaddress.pyi
index 9df6bab7c..6d49eb8bd 100644
--- a/stdlib/ipaddress.pyi
+++ b/stdlib/ipaddress.pyi
@@ -137,7 +137,7 @@ class IPv4Address(_BaseV4, _BaseAddress):
         def ipv6_mapped(self) -> IPv6Address: ...
 
 class IPv4Network(_BaseV4, _BaseNetwork[IPv4Address]):
-    def __init__(self, address: object, strict: bool = ...) -> None: ...
+    def __init__(self, address: object, strict: bool = True) -> None: ...
 
 class IPv4Interface(IPv4Address):
     netmask: IPv4Address
@@ -197,7 +197,7 @@ class IPv6Address(_BaseV6, _BaseAddress):
     def __eq__(self, other: object) -> bool: ...
 
 class IPv6Network(_BaseV6, _BaseNetwork[IPv6Address]):
-    def __init__(self, address: object, strict: bool = ...) -> None: ...
+    def __init__(self, address: object, strict: bool = True) -> None: ...
     @property
     def is_site_local(self) -> bool: ...