diff --git a/dev-ml/uri/metadata.xml b/dev-ml/uri/metadata.xml
index 982af7c50a..57acd83577 100644
--- a/dev-ml/uri/metadata.xml
+++ b/dev-ml/uri/metadata.xml
@@ -9,4 +9,8 @@
 	<upstream>
 		<remote-id type="github">mirage/ocaml-uri</remote-id>
 	</upstream>
+	<use>
+		<flag name="re">This is an OCaml implementation of the RFC3986 specification for parsing URI or URLs</flag>
+		<flag name="sexp">ocaml-uri with sexp support</flag>
+	</use>
 </pkgmetadata>
diff --git a/dev-ml/uri/uri-4.2.0.ebuild b/dev-ml/uri/uri-4.2.0.ebuild
index e8103d4f00..4ece589c32 100644
--- a/dev-ml/uri/uri-4.2.0.ebuild
+++ b/dev-ml/uri/uri-4.2.0.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 
-inherit dune
+inherit dune multiprocessing
 
 DESCRIPTION="RFC3986 URI parsing library for OCaml"
 HOMEPAGE="https://github.com/mirage/ocaml-uri"
@@ -13,19 +13,42 @@ S="${WORKDIR}/ocaml-${P}"
 LICENSE="ISC"
 SLOT="0/${PV}"
 KEYWORDS="~amd64"
-IUSE="ocamlopt"
+IUSE="ocamlopt re sexp test"
 
 RDEPEND="
 	dev-ml/angstrom
-	dev-ml/ppx_sexp_conv
-	dev-ml/re
-	dev-ml/sexplib0
 	dev-ml/stringext
+
+	re? (
+		dev-ml/re
+	)
+	sexp? (
+		dev-ml/ppx_sexp_conv
+		dev-ml/sexplib0
+	)
 "
-DEPEND="${RDEPEND}"
+DEPEND="
+	${RDEPEND}
+	test? (
+		dev-ml/ounit
+		dev-ml/ppx_sexp_conv
+	)
+"
+
+RESTRICT="!test? ( test )"
+
+src_compile() {
+	local pkgs="uri"
+	for u in sexp re ; do
+		if use ${u} ; then
+			pkgs="${pkgs},uri-${u}"
+		fi
+	done
+	dune build --only-packages "${pkgs}" -j $(makeopts_jobs) --profile release || die
+}
 
 src_install() {
 	dune_src_install uri
-	dune_src_install uri-re
-	dune_src_install uri-sexp
+	use re && dune_src_install uri-re
+	use sexp && dune_src_install uri-sexp
 }