diff --git a/stdlib/3/sys.pyi b/stdlib/3/sys.pyi
index 0e7b47600..3f856bbc9 100644
--- a/stdlib/3/sys.pyi
+++ b/stdlib/3/sys.pyi
@@ -188,6 +188,10 @@ def intern(string: str) -> str: ...
 if sys.version_info >= (3, 5):
     def is_finalizing() -> bool: ...
 
+if sys.version_info >= (3, 7):
+    __breakpointhook__: Any  # contains the original value of breakpointhook
+    def breakpointhook(*args: Any, **kwargs: Any) -> Any: ...
+
 def setcheckinterval(interval: int) -> None: ...  # deprecated
 def setdlopenflags(n: int) -> None: ...  # Linux only
 def setrecursionlimit(limit: int) -> None: ...