diff --git a/_oasis b/_oasis
index 1709ba2..c5dd333 100644
--- a/_oasis
+++ b/_oasis
@@ -27,6 +27,10 @@ Description:
 # | The toplevel                                                      |
 # +-------------------------------------------------------------------+
 
+Flag camlp4
+  Description: camlp4 support
+  Default: true
+
 Library "optcomp"
   Install: false
   Path: syntax
@@ -51,6 +55,8 @@ Library utop
   XMETARequires: findlib, lambda-term
 
 Library "utop-camlp4"
+  Build$: flag(camlp4)
+  Install$: flag(camlp4)
   FindlibName: camlp4
   FindlibParent: utop
   Path: src/camlp4
diff --git a/opam b/opam
index 40321b4..f4c499d 100644
--- a/opam
+++ b/opam
@@ -4,7 +4,7 @@ authors: ["Jérémie Dimino"]
 homepage: "https://github.com/diml/utop"
 license: "BSD3"
 build: [
-  ["./configure" "--prefix" prefix]
+  ["./configure" "--prefix" prefix "--%{camlp4:enable}%-camlp4"]
   [make]
   [make "install"]
 ]