diff --git a/inttest/port/c_src/test1.c b/inttest/port/c_src/test1.c
new file mode 100644
index 0000000..4073ed6
--- /dev/null
+++ b/inttest/port/c_src/test1.c
@@ -0,0 +1 @@
+#include "test1.h"
diff --git a/inttest/port/c_src/test1.h b/inttest/port/c_src/test1.h
new file mode 100644
index 0000000..e69de29
diff --git a/inttest/port/c_src/test2.c b/inttest/port/c_src/test2.c
new file mode 100644
index 0000000..98cc459
--- /dev/null
+++ b/inttest/port/c_src/test2.c
@@ -0,0 +1 @@
+#include "test2.h"
diff --git a/inttest/port/c_src/test2.h b/inttest/port/c_src/test2.h
new file mode 100644
index 0000000..4073ed6
--- /dev/null
+++ b/inttest/port/c_src/test2.h
@@ -0,0 +1 @@
+#include "test1.h"
diff --git a/inttest/port/port_rt.erl b/inttest/port/port_rt.erl
new file mode 100644
index 0000000..34324da
--- /dev/null
+++ b/inttest/port/port_rt.erl
@@ -0,0 +1,76 @@
+%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+
+-module(port_rt).
+-export([files/0,
+         run/1]).
+
+-include_lib("eunit/include/eunit.hrl").
+
+files() ->
+    [
+     {copy, "../../rebar", "rebar"},
+     {copy, "rebar.config", "rebar.config"},
+     {copy, "c_src", "c_src"},
+     {create, "ebin/foo.app", app(foo, [])}
+    ].
+
+run(_Dir) ->
+    % wait a bit for new files to have different timestamps
+    wait(),
+    % test.so is created during first compile
+    ?assertEqual(0, filelib:last_modified("priv/test.so")),
+    ?assertMatch({ok, _}, retest_sh:run("./rebar compile", [])),
+    TestSo1 = filelib:last_modified("priv/test.so"),
+    ?assert(TestSo1 > 0),
+    wait(),
+    % nothing happens during second compile
+    ?assertMatch({ok, _}, retest_sh:run("./rebar compile", [])),
+    TestSo2 = filelib:last_modified("priv/test.so"),
+    Test1o2 = filelib:last_modified("c_src/test1.o"),
+    Test2o2 = filelib:last_modified("c_src/test2.o"),
+    ?assertEqual(TestSo1, TestSo2),
+    ?assert(TestSo1 >= Test1o2),
+    ?assert(TestSo1 >= Test2o2),
+    wait(),
+    % when test2.c changes, at least test2.o and test.so are rebuilt
+    ?assertMatch({ok, _}, retest_sh:run("touch c_src/test2.c", [])),
+    ?assertMatch({ok, _}, retest_sh:run("./rebar compile", [])),
+    TestSo3 = filelib:last_modified("priv/test.so"),
+    Test2o3 = filelib:last_modified("c_src/test2.o"),
+    ?assert(TestSo3 > TestSo2),
+    ?assert(Test2o3 > TestSo2),
+    wait(),
+    % when test2.h changes, at least test2.o and test.so are rebuilt
+    ?assertMatch({ok, _}, retest_sh:run("touch c_src/test2.h", [])),
+    ?assertMatch({ok, _}, retest_sh:run("./rebar compile", [])),
+    TestSo4 = filelib:last_modified("priv/test.so"),
+    Test2o4 = filelib:last_modified("c_src/test2.o"),
+    ?assert(TestSo4 > TestSo3),
+    ?assert(Test2o4 > TestSo3),
+    wait(),
+    % when test1.h changes, everything is rebuilt
+    ?assertMatch({ok, _}, retest_sh:run("touch c_src/test1.h", [])),
+    ?assertMatch({ok, _}, retest_sh:run("./rebar compile", [])),
+    TestSo5 = filelib:last_modified("priv/test.so"),
+    Test1o5 = filelib:last_modified("c_src/test1.o"),
+    Test2o5 = filelib:last_modified("c_src/test2.o"),
+    ?assert(TestSo5 > TestSo4),
+    ?assert(Test1o5 > TestSo4),
+    ?assert(Test2o5 > TestSo4),
+    ok.
+
+wait() ->
+    timer:sleep(1000).
+
+%%
+%% Generate the contents of a simple .app file
+%%
+app(Name, Modules) ->
+    App = {application, Name,
+           [{description, atom_to_list(Name)},
+            {vsn, "1"},
+            {modules, Modules},
+            {registered, []},
+            {applications, [kernel, stdlib]}]},
+    io_lib:format("~p.\n", [App]).
diff --git a/inttest/port/rebar.config b/inttest/port/rebar.config
new file mode 100644
index 0000000..a941218
--- /dev/null
+++ b/inttest/port/rebar.config
@@ -0,0 +1 @@
+{port_specs, [{"priv/test.so", ["c_src/*.c"]}]}.