diff --git a/src/c/unixsys.d b/src/c/unixsys.d
index b2f18eb99..efc26019f 100644
--- a/src/c/unixsys.d
+++ b/src/c/unixsys.d
@@ -370,11 +370,7 @@ si_run_program_inner(cl_object command, cl_object argv, cl_object environ) {
   parent_read = ecl_fixnum(ecl_nth_value(the_env, 2));
   parent_error = ecl_fixnum(ecl_nth_value(the_env, 3));
 
-  stream_write = ecl_make_stream_from_fd(command, parent_write,
-                                         ecl_smm_output, 8,
-                                         ECL_STREAM_DEFAULT_FORMAT,
-                                         @':default');
-
+  /* descriptor is closed in the stream finalizer */
   stream_read = ecl_make_stream_from_fd(command, parent_read,
                                         ecl_smm_input, 8,
                                         ECL_STREAM_DEFAULT_FORMAT,
@@ -384,8 +380,10 @@ si_run_program_inner(cl_object command, cl_object argv, cl_object environ) {
   exit_status = ecl_nth_value(the_env, 1);
 
   /* close unused descriptors */
+  close(parent_write);
   close(parent_error);
-  @(return cl_make_two_way_stream(stream_read, stream_write) exit_status)
+
+  @(return stream_read exit_status)
 }
 
 cl_object
diff --git a/src/cmp/proclamations.lsp b/src/cmp/proclamations.lsp
index 708e32f95..05884ce53 100644
--- a/src/cmp/proclamations.lsp
+++ b/src/cmp/proclamations.lsp
@@ -1347,7 +1347,7 @@
                                             (or null fixnum)))
 (proclamation si:killpid (fixnum fixnum) fixnum)
 (proclamation si:run-program-inner (string (or list string) list)
-              (values two-way-stream integer))
+              (values file-stream integer))
 (proclamation si:spawn-subprocess (string (or list string) list t t t)
               (values (or null integer) fixnum fixnum fixnum))
 (proclamation ext:terminate-process (t &optional gen-bool) null)