diff --git a/src/rebar_app_utils.erl b/src/rebar_app_utils.erl
index 744af4c..7794b5b 100644
--- a/src/rebar_app_utils.erl
+++ b/src/rebar_app_utils.erl
@@ -27,6 +27,8 @@
 -module(rebar_app_utils).
 
 -export([is_app_dir/0, is_app_dir/1,
+         is_app_src/1,
+         app_src_to_app/1,
          app_name/1,
          app_applications/1,
          app_vsn/1]).
@@ -43,14 +45,31 @@ is_app_dir() ->
     is_app_dir(rebar_util:get_cwd()).
 
 is_app_dir(Dir) ->
-    Fname = filename:join([Dir, "ebin/*.app"]),
-    case filelib:wildcard(Fname) of
-        [AppFile] ->
-            {true, AppFile};
+    AppSrc = filename:join(Dir, "src/*.app.src"),
+    case filelib:wildcard(AppSrc) of
+        [AppSrcFile] ->
+            ?DEBUG("Found app.src: ~p\n", [AppSrcFile]),
+            {true, AppSrcFile};
         _ ->
-            false
+            App = filename:join([Dir, "ebin/*.app"]),
+            case filelib:wildcard(App) of
+                [AppFile] ->
+                    ?DEBUG("Found .app: ~p\n", [AppFile]),
+                    {true, AppFile};
+                _ ->
+                    false
+            end
     end.
 
+
+is_app_src(Filename) ->
+    %% If removing the extension .app.src yields a shorter name,
+    %% this is an .app.src file.
+    Filename /= filename:rootname(Filename, ".app.src").
+
+app_src_to_app(Filename) ->
+    filename:join("ebin", filename:basename(Filename, ".app.src") ++ ".app").
+
 app_name(AppFile) ->
     case load_app_file(AppFile) of
         {ok, AppName, _} ->
@@ -79,7 +98,6 @@ app_vsn(AppFile) ->
     end.
 
 
-
 %% ===================================================================
 %% Internal functions
 %% ===================================================================
diff --git a/src/rebar_otp_app.erl b/src/rebar_otp_app.erl
index 8db1044..bcc13fd 100644
--- a/src/rebar_otp_app.erl
+++ b/src/rebar_otp_app.erl
@@ -27,6 +27,7 @@
 -module(rebar_otp_app).
 
 -export([compile/2,
+         clean/2,
          install/2]).
 
 -include("rebar.hrl").
@@ -36,12 +37,34 @@
 %% ===================================================================
 
 compile(_Config, File) ->
-    %% Load the app name and version from the .app file and construct
-    %% the app identifier
-    {ok, AppName, AppData} = rebar_app_utils:load_app_file(File),
-    validate_name(AppName, File),
-    validate_modules(AppName, proplists:get_value(modules, AppData)),
-    ok.
+    %% If we get an .app.src file, it needs to be pre-processed and
+    %% written out as a ebin/*.app file. That resulting file will then
+    %% be validated as usual.
+    case rebar_app_utils:is_app_src(File) of
+        true ->
+            AppFile = preprocess(File);
+        false ->
+            AppFile = File
+    end,
+
+    %% Load the app file and validate it.
+    case rebar_app_utils:load_app_file(AppFile) of
+        {ok, AppName, AppData} ->
+            validate_name(AppName, AppFile),
+            validate_modules(AppName, proplists:get_value(modules, AppData));
+        {error, Reason} ->
+            ?ABORT("Failed to load app file ~s: ~p\n", [AppFile, Reason])
+    end.
+
+clean(_Config, File) ->
+    %% If the app file is a .app.src, delete the generated .app file
+    case rebar_app_utils:is_app_src(File) of
+        true ->
+            file:delete(rebar_app_utils:app_src_to_app(File)),
+            ok;
+        false ->
+            ok
+    end.
 
 
 install(Config, File) ->
@@ -116,6 +139,25 @@ install_binaries([Bin | Rest], AppDir, BinDir) ->
     rebar_file_utils:ln_sf(FqBin, BinDir),
     install_binaries(Rest, AppDir, BinDir).
 
+preprocess(AppSrcFile) ->
+    case rebar_app_utils:load_app_file(AppSrcFile) of
+        {ok, AppName, AppData} ->
+            %% Get a list of all the modules available in ebin/ and update
+            %% the app data accordingly
+            A1 = lists:keystore(modules, 1, AppData, {modules, ebin_modules()}),
+
+            %% Build the final spec as a string
+            Spec = io_lib:format("~p.\n", [{application, AppName, A1}]),
+
+            %% Setup file .app filename and write new contents
+            AppFile = rebar_app_utils:app_src_to_app(AppSrcFile),
+            ok = file:write_file(AppFile, Spec),
+            AppFile;
+
+        {error, Reason} ->
+            ?ABORT("Failed to read ~s for preprocessing: ~p\n", [AppSrcFile, Reason])
+    end.
+
 
 validate_name(AppName, File) ->
     %% Convert the .app file name to an atom -- check it against the identifier within the file
@@ -136,7 +178,7 @@ validate_modules(AppName, undefined) ->
 validate_modules(AppName, Mods) ->
     %% Construct two sets -- one for the actual .beam files in ebin/ and one for the modules
     %% listed in the .app file
-    EbinSet = ordsets:from_list([rebar_utils:beam_to_mod("ebin", N) || N <- rebar_utils:beams("ebin")]),
+    EbinSet = ordsets:from_list(ebin_modules()),
     ModSet = ordsets:from_list(Mods),
 
     %% Identify .beam files listed in the .app, but not present in ebin/
@@ -160,3 +202,6 @@ validate_modules(AppName, Mods) ->
                    [AppName, Msg2]),
             ?FAIL
     end.
+
+ebin_modules() ->
+    lists:sort([rebar_utils:beam_to_mod("ebin", N) || N <- rebar_utils:beams("ebin")]).
diff --git a/src/rebar_port_compiler.erl b/src/rebar_port_compiler.erl
index 6960a5f..f38b621 100644
--- a/src/rebar_port_compiler.erl
+++ b/src/rebar_port_compiler.erl
@@ -352,12 +352,8 @@ so_specs(Config, AppFile, Bins) ->
                          undefined ->
                              %% Ok, neither old nor new form is available. Use the app name and
                              %% generate a sensible default.
-                             case rebar_app_utils:load_app_file(AppFile) of
-                                 {ok, AppName, _} ->
-                                     ?FMT("priv/~s", [lists:concat([AppName, "_drv.so"])]);
-                                 error ->
-                                     ?FAIL
-                             end;
+                             AppName = rebar_app_utils:app_name(AppFile),
+                             ?FMT("priv/~s", [lists:concat([AppName, "_drv.so"])]);
 
                          AName ->
                              %% Old form is available -- use it