diff --git a/CHANGELOG.md b/CHANGELOG.md
index 290eac5..2b6ee68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Fixed
 
 - Deleting a link pointing to a directory now delete the link instead of the directory content
+- Flagging a stream as blocking was set as non-blocking
 
 ## 4.1.2 - 2026-08-01
 
diff --git a/src/Internal/Stream/AmbientAuthority.php b/src/Internal/Stream/AmbientAuthority.php
index 7d08128..d0e69fa 100644
--- a/src/Internal/Stream/AmbientAuthority.php
+++ b/src/Internal/Stream/AmbientAuthority.php
@@ -122,7 +122,7 @@ public function blocking(): Maybe
             return Maybe::nothing();
         }
 
-        $return = \stream_set_blocking($this->resource, false);
+        $return = \stream_set_blocking($this->resource, true);
 
         if ($return === false) {
             /** @var Maybe<SideEffect> */