diff --git a/packages/graphics/scripts/opam b/packages/graphics/scripts/opam
index 786b00fad2c..511fcb4ad4e 100644
--- a/packages/graphics/scripts/opam
+++ b/packages/graphics/scripts/opam
@@ -10,6 +10,7 @@ authors: [ "Xavier Leroy"
 homepage: "https://ocaml.org"
 license: "LGPL-2.1 with OCaml linking exception"
 build: [
+  ["chmod" "+x" "install.sh"]
   ["./install.sh" "build" "%{ocaml:preinstalled}%" "%{ocaml:lib}%" make "allopt" {ocaml:native}]
 ]
 install: [