diff --git a/opam-0install-cudf.opam b/opam-0install-cudf.opam
index 9cf1621..ab00cbe 100644
--- a/opam-0install-cudf.opam
+++ b/opam-0install-cudf.opam
@@ -25,6 +25,7 @@ depends: [
   "cudf" {>= "0.10"}
   "ocaml" {>= "4.08.0"}
   "0install-solver" {>= "2.18"}
+  "alcotest" {with-test}
 ]
 build: ["dune" "build" "-p" name "-j" jobs]
 run-test: ["dune" "test" "-p" name "-j" jobs]
diff --git a/test/cudf/dune b/test/cudf/dune
new file mode 100644
index 0000000..beefe6b
--- /dev/null
+++ b/test/cudf/dune
@@ -0,0 +1,4 @@
+(test
+ (name test)
+ (package opam-0install-cudf)
+ (libraries alcotest opam-0install-cudf))
diff --git a/test/cudf/test.ml b/test/cudf/test.ml
new file mode 100644
index 0000000..323aea8
--- /dev/null
+++ b/test/cudf/test.ml
@@ -0,0 +1,87 @@
+let universe =
+  Cudf.load_universe [
+    {Cudf.default_package with package = "a"; version = 1};
+    {Cudf.default_package with package = "a"; version = 2};
+    {Cudf.default_package with package = "a"; version = 3};
+    {Cudf.default_package with package = "a"; version = 4};
+
+    {Cudf.default_package with package = "b"; version = 1};
+    {Cudf.default_package with package = "b"; version = 2; pkg_extra = [("avoid-version", `Int 1)]};
+    {Cudf.default_package with package = "b"; version = 3; pkg_extra = [("avoid-version", `Int 0)]};
+    {Cudf.default_package with package = "b"; version = 4};
+
+    {Cudf.default_package with package = "c"; version = 1; pkg_extra = [("avoid-version", `Int 1)]};
+    {Cudf.default_package with package = "c"; version = 2};
+    {Cudf.default_package with package = "c"; version = 3};
+    {Cudf.default_package with package = "c"; version = 4; pkg_extra = [("avoid-version", `Int 0)]};
+
+    {Cudf.default_package with package = "d"; version = 1; pkg_extra = [("avoid-version", `Int 0)]};
+    {Cudf.default_package with package = "d"; version = 2};
+    {Cudf.default_package with package = "d"; version = 3};
+    {Cudf.default_package with package = "d"; version = 4; pkg_extra = [("avoid-version", `Int 1)]};
+  ]
+
+let solve ?prefer_oldest req =
+  let x = Opam_0install_cudf.create ?prefer_oldest ~constraints:[] universe in
+  match Opam_0install_cudf.solve x req with
+  | Ok sel -> Ok (Opam_0install_cudf.packages_of_result sel)
+  | Error diag -> Error (Opam_0install_cudf.diagnostics ~verbose:true diag)
+
+let simple_solve () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("a", 4)])
+    (solve [("a", `Essential)])
+
+let simple_oldest () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("a", 1)])
+    (solve ~prefer_oldest:true [("a", `Essential)])
+
+let simple_avoid_1 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("b", 4)])
+    (solve [("b", `Essential)])
+
+let oldest_avoid_1 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("b", 1)])
+    (solve ~prefer_oldest:true [("b", `Essential)])
+
+let simple_avoid_2 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("c", 4)])
+    (solve [("c", `Essential)])
+
+let oldest_avoid_2 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("c", 2)])
+    (solve ~prefer_oldest:true [("c", `Essential)])
+
+let simple_avoid_3 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("d", 3)])
+    (solve [("d", `Essential)])
+
+let oldest_avoid_3 () =
+  Alcotest.(check (result (list (pair string int)) string))
+    "equal" (Ok [("d", 1)])
+    (solve ~prefer_oldest:true [("d", `Essential)])
+
+let () =
+  Alcotest.run "cudf"
+    [
+      ( "simple solve",
+        [
+          Alcotest.test_case "normal" `Quick simple_solve;
+          Alcotest.test_case "oldest" `Quick simple_oldest;
+        ] );
+      ( "avoid-version",
+        [
+          Alcotest.test_case "normal 1" `Quick simple_avoid_1;
+          Alcotest.test_case "oldest 1" `Quick oldest_avoid_2;
+          Alcotest.test_case "normal 2" `Quick simple_avoid_2;
+          Alcotest.test_case "oldest 2" `Quick oldest_avoid_2;
+          Alcotest.test_case "normal 3" `Quick simple_avoid_3;
+          Alcotest.test_case "oldest 3" `Quick oldest_avoid_3;
+        ] );
+    ]