diff --git a/docker/extensions.txt b/docker/extensions.txt
index 776c5706..d170233f 100755
--- a/docker/extensions.txt
+++ b/docker/extensions.txt
@@ -28,7 +28,7 @@ pdo_sqlite
 phar
 posix
 ^protobuf
-readline
+^readline
 redis
 shmop
 simplexml