diff --git a/src/rebar_port_compiler.erl b/src/rebar_port_compiler.erl
index 4163dd4..22acff6 100644
--- a/src/rebar_port_compiler.erl
+++ b/src/rebar_port_compiler.erl
@@ -487,8 +487,7 @@ expand_keys_in_value([Key | Rest], Value, Vars) ->
 expand_command(TmplName, Env, InFiles, OutFile) ->
     Cmd0 = proplists:get_value(TmplName, Env),
     Cmd1 = rebar_utils:expand_env_variable(Cmd0, "PORT_IN_FILES", InFiles),
-    Cmd2 = rebar_utils:expand_env_variable(Cmd1, "PORT_OUT_FILE", OutFile),
-    re:replace(Cmd2, "\\\$\\w+|\\\${\\w+}", "", [global, {return, list}]).
+    rebar_utils:expand_env_variable(Cmd1, "PORT_OUT_FILE", OutFile).
 
 %%
 %% Given a string, determine if it is expandable
diff --git a/src/rebar_utils.erl b/src/rebar_utils.erl
index 8f71bab..abe837a 100644
--- a/src/rebar_utils.erl
+++ b/src/rebar_utils.erl
@@ -337,10 +337,12 @@ get_deprecated_3(Get, Config, OldOpt, NewOpt, Default, When) ->
 patch_on_windows(Cmd, Env) ->
     case os:type() of
         {win32,nt} ->
-            "cmd /q /c "
+            Cmd1 = "cmd /q /c "
                 ++ lists:foldl(fun({Key, Value}, Acc) ->
                                        expand_env_variable(Acc, Key, Value)
-                               end, Cmd, Env);
+                               end, Cmd, Env),
+            %% Remove left-over vars
+            re:replace(Cmd1, "\\\$\\w+|\\\${\\w+}", "", [global, {return, list}]);
         _ ->
             Cmd
     end.