diff --git a/opam/opam b/opam/opam
index 882e41d655a5f93f1858f5097217c5266cfe468b..2a7aee3a9c488cee7222504f9d81f1fe86197af3 100644
--- a/opam/opam
+++ b/opam/opam
@@ -87,7 +87,7 @@ tags: [
 ]
 
 build: [
-  ["autoconf"] {pinned}
+  ["autoconf"] {dev}
   ["./configure" "--prefix" prefix
                  "--mandir=%{man}%"
   ]