diff --git a/src/c/unixsys.d b/src/c/unixsys.d
index f54979f45..ef98fcfbb 100644
--- a/src/c/unixsys.d
+++ b/src/c/unixsys.d
@@ -568,9 +568,9 @@ si_run_program_internal(cl_object command, cl_object argv,
     cl_object env_buffer;
     char *env = NULL;
 
-    /* Enclose each argument, as well as the file name
-       in double quotes, to avoid problems when these
-       arguments or file names have spaces */
+    /* Command is passed as is from argv. It is responsibility of
+       higher level interface to decide, whenever arguments should be
+       quoted or left as-is.*/
     command = ecl_null_terminated_base_string(argv);
 
     if (!Null(environ)) {
@@ -628,10 +628,11 @@ si_run_program_internal(cl_object command, cl_object argv,
     if (child_stdout) CloseHandle(child_stdout);
     if (child_stderr) CloseHandle(child_stderr);
   }
-#elif !defined(NACL) /* mingw */
+#elif !defined(NACL) /* All POSIX but NaCL/pNaCL */
   {
     int child_stdin, child_stdout, child_stderr;
     int pipe_fd[2];
+    argv = ecl_nconc(argv, ecl_list1(ECL_NIL));
     argv = _ecl_funcall3(@'coerce', argv, @'vector');
 
     create_descriptor(input,  @':input',  &child_stdin,  &parent_write);
diff --git a/src/lsp/process.lsp b/src/lsp/process.lsp
index 76f8229af..cfaaba3ae 100644
--- a/src/lsp/process.lsp
+++ b/src/lsp/process.lsp
@@ -104,8 +104,9 @@
                                     :direction :output
                                     :if-exists if-error-exists)))
 
-    (let ((args (prepare-args (cons command argv))))
-      (si:run-program-internal (si:copy-to-simple-base-string command) args
+    (let* ((args (prepare-args (cons command argv)))
+           (progname (car args)))
+      (si:run-program-internal progname args
                                input output error
                                wait environ external-format))))