diff --git a/src/libslic3r/GCode/PostProcessor.cpp b/src/libslic3r/GCode/PostProcessor.cpp
index 89456dfca..ced74e3eb 100644
--- a/src/libslic3r/GCode/PostProcessor.cpp
+++ b/src/libslic3r/GCode/PostProcessor.cpp
@@ -20,11 +20,6 @@
 #include <Windows.h>
 #include <shellapi.h>
 
-//! macro used to mark string used at localization,
-//! return same string
-#define L(s) (s)
-#define _(s) Slic3r::I18N::translate(s)
-
 // https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/
 // This routine appends the given argument to a command line such that CommandLineToArgvW will return the argument string unchanged.
 // Arguments in a command line should be separated by spaces; this function does not add these spaces.
@@ -190,6 +185,11 @@ static int run_script(const std::string &script, const std::string &gcode, std::
 
 namespace Slic3r {
 
+//! macro used to mark string used at localization,
+//! return same string
+#define L(s) (s)
+#define _(s) Slic3r::I18N::translate(s)
+
 // Run post processing script / scripts if defined.
 // Returns true if a post-processing script was executed.
 // Returns false if no post-processing script was defined.
@@ -285,10 +285,10 @@ bool run_post_process_scripts(std::string &src_path, bool make_copy, const std::
                     throw Slic3r::RuntimeError(msg);
                 }
                 if (! boost::filesystem::exists(gcode_file)) {
-                    const std::string msg = (boost::format(_(
+                    const std::string msg = (boost::format(_(L(
                         "Post-processing script %1% failed.\n\n"
                         "The post-processing script is expected to change the G-code file %2% in place, but the G-code file was deleted and likely saved under a new name.\n"
-                        "Please adjust the post-processing script to change the G-code in place and consult the manual on how to optionally rename the post-processed G-code file.\n"))
+                        "Please adjust the post-processing script to change the G-code in place and consult the manual on how to optionally rename the post-processed G-code file.\n")))
                         % script % path).str();
                     BOOST_LOG_TRIVIAL(error) << msg;
                     throw Slic3r::RuntimeError(msg);