diff --git a/src/configurator/jbuild b/src/configurator/jbuild
index 2b696467..2b11a82f 100644
--- a/src/configurator/jbuild
+++ b/src/configurator/jbuild
@@ -1,5 +1,6 @@
 (library
  ((name configurator)
+  (public_name jbuilder.configurator)
   (libraries (stdune ocaml_config))
   (flags (:standard -safe-string (:include flags/flags.sexp)))
   (preprocess no_preprocessing)))
diff --git a/src/ocaml-config/jbuild b/src/ocaml-config/jbuild
index df51c131..3fa057e4 100644
--- a/src/ocaml-config/jbuild
+++ b/src/ocaml-config/jbuild
@@ -2,5 +2,6 @@
 
 (library
  ((name      ocaml_config)
+  (public_name jbuilder.ocaml_config)
   (libraries (stdune usexp))
-  (synopsis  "Interpret the output of 'ocamlc -config'")))
+  (synopsis  "[Internal] Interpret the output of 'ocamlc -config'")))
diff --git a/src/ocaml-config/ocaml_config.mli b/src/ocaml-config/ocaml_config.mli
index 793377e5..fbdbb92b 100644
--- a/src/ocaml-config/ocaml_config.mli
+++ b/src/ocaml-config/ocaml_config.mli
@@ -1,4 +1,6 @@
-(** Represent the output of [ocamlc -config] *)
+(** Represent the output of [ocamlc -config].
+
+    This library is internal to jbuilder and guarantees no API stability. *)
 
 open Stdune
 
diff --git a/src/stdune/caml/caml.ml b/src/stdune/caml/caml.ml
index 82dc6ca9..a43c1037 100644
--- a/src/stdune/caml/caml.ml
+++ b/src/stdune/caml/caml.ml
@@ -1,3 +1,5 @@
+(** This library is internal to jbuilder and guarantees no API stability. *)
+
 module Filename = Filename
 module String   = String
 module Char     = Char
diff --git a/src/stdune/caml/jbuild b/src/stdune/caml/jbuild
index 1886d286..04b16834 100644
--- a/src/stdune/caml/jbuild
+++ b/src/stdune/caml/jbuild
@@ -1,3 +1,4 @@
 (library
  ((name caml)
-  (synopsis "Wrapped version of the OCaml stdlib")))
+  (public_name jbuilder.caml)
+  (synopsis "[Internal] Wrapped version of the OCaml stdlib")))
diff --git a/src/stdune/jbuild b/src/stdune/jbuild
index 36e4eaa0..b1f82de0 100644
--- a/src/stdune/jbuild
+++ b/src/stdune/jbuild
@@ -1,4 +1,5 @@
 (library
  ((name stdune)
-  (synopsis "Standard library of Dune")
+  (public_name jbuilder.stdune)
+  (synopsis "[Internal] Standard library of Dune")
   (libraries (caml unix))))
diff --git a/src/usexp/jbuild b/src/usexp/jbuild
index 2c10cbe2..53b46ee9 100644
--- a/src/usexp/jbuild
+++ b/src/usexp/jbuild
@@ -1,6 +1,9 @@
 (jbuild_version 1)
 
-(library ((name usexp)))
+(library
+ ((name usexp)
+  (synopsis "[Internal] S-expression library")
+  (public_name jbuilder.usexp)))
 
 (rule
  (with-stdout-to table.ml.gen (run gen/gen_parser_automaton.exe)))
diff --git a/src/usexp/usexp.mli b/src/usexp/usexp.mli
index 5fa3a242..27e03dc7 100644
--- a/src/usexp/usexp.mli
+++ b/src/usexp/usexp.mli
@@ -1,4 +1,6 @@
-(** Parsing of s-expressions *)
+(** Parsing of s-expressions.
+
+    This library is internal to jbuilder and guarantees no API stability.*)
 
 module Atom : sig
   type t = private A of string [@@unboxed]
diff --git a/test/blackbox-tests/jbuild b/test/blackbox-tests/jbuild
index 01edbb92..becfd2ea 100644
--- a/test/blackbox-tests/jbuild
+++ b/test/blackbox-tests/jbuild
@@ -459,3 +459,13 @@
     (progn
      (run ${exe:cram.exe} run.t)
      (diff? run.t run.t.corrected))))))
+
+(alias
+ ((name runtest)
+  (deps ((package jbuilder)
+         (files_recursively_in test-cases/configurator)))
+  (action
+   (chdir test-cases/configurator
+    (progn
+     (run ${exe:cram.exe} run.t)
+     (diff? run.t run.t.corrected))))))
diff --git a/test/blackbox-tests/test-cases/configurator/c_test/jbuild b/test/blackbox-tests/test-cases/configurator/c_test/jbuild
new file mode 100644
index 00000000..0f63b54a
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/c_test/jbuild
@@ -0,0 +1,5 @@
+(jbuild_version 1)
+
+(executable
+ ((name run)
+  (libraries (jbuilder.configurator))))
diff --git a/test/blackbox-tests/test-cases/configurator/c_test/run.ml b/test/blackbox-tests/test-cases/configurator/c_test/run.ml
new file mode 100644
index 00000000..dc3a9f08
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/c_test/run.ml
@@ -0,0 +1,15 @@
+
+let () =
+  Configurator.main ~name:"c_test" (fun t ->
+    let c_result =
+      Configurator.c_test t {c|
+#include <stdio.h>
+int main()
+{
+   printf("Hello, World!");
+   return 0;
+}
+|c} in
+    assert c_result;
+    print_endline "Successfully compiled c program"
+  )
diff --git a/test/blackbox-tests/test-cases/configurator/config/jbuild b/test/blackbox-tests/test-cases/configurator/config/jbuild
new file mode 100644
index 00000000..0f63b54a
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/config/jbuild
@@ -0,0 +1,5 @@
+(jbuild_version 1)
+
+(executable
+ ((name run)
+  (libraries (jbuilder.configurator))))
diff --git a/test/blackbox-tests/test-cases/configurator/config/run.ml b/test/blackbox-tests/test-cases/configurator/config/run.ml
new file mode 100644
index 00000000..e7e39784
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/config/run.ml
@@ -0,0 +1,6 @@
+let () =
+  Configurator.main ~name:"config" (fun t ->
+    match Configurator.ocaml_config_var t "version" with
+    | None -> failwith "version is absent"
+    | Some _ -> print_endline "version is present"
+  )
diff --git a/test/blackbox-tests/test-cases/configurator/import-define/jbuild b/test/blackbox-tests/test-cases/configurator/import-define/jbuild
new file mode 100644
index 00000000..0f63b54a
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/import-define/jbuild
@@ -0,0 +1,5 @@
+(jbuild_version 1)
+
+(executable
+ ((name run)
+  (libraries (jbuilder.configurator))))
diff --git a/test/blackbox-tests/test-cases/configurator/import-define/run.ml b/test/blackbox-tests/test-cases/configurator/import-define/run.ml
new file mode 100644
index 00000000..42a9ab20
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/import-define/run.ml
@@ -0,0 +1,15 @@
+let () =
+  let module C_define = Configurator.C_define in
+  Configurator.main ~name:"c_test" (fun t ->
+    assert (
+      C_define.import t
+        ~includes:["caml/config.h"]
+        [ "CAML_CONFIG_H", C_define.Type.Switch
+        ; "Page_log", C_define.Type.Int
+        ] =
+      [ "CAML_CONFIG_H", C_define.Value.Switch true
+      ; "Page_log", Int 12
+      ]
+    );
+    print_endline "Successfully import #define's"
+  )
diff --git a/test/blackbox-tests/test-cases/configurator/run.t b/test/blackbox-tests/test-cases/configurator/run.t
new file mode 100644
index 00000000..9fbda06e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/configurator/run.t
@@ -0,0 +1,11 @@
+Show that config values are present
+  $ jbuilder exec config/run.exe
+  version is present
+
+We're able to compile C program sucessfully
+  $ jbuilder exec c_test/run.exe
+  Successfully compiled c program
+
+Importing #define's from code is successful
+  $ jbuilder exec import-define/run.exe
+  Successfully import #define's