diff --git a/stdlib/errno.pyi b/stdlib/errno.pyi
index b053604fc..5180b5940 100644
--- a/stdlib/errno.pyi
+++ b/stdlib/errno.pyi
@@ -36,6 +36,7 @@ EMLINK: int
 EPIPE: int
 EDOM: int
 ERANGE: int
+EDEADLK: int
 EDEADLCK: int
 ENAMETOOLONG: int
 ENOLCK: int