diff --git a/app/main.c b/app/main.c
index a2da39737a..0edc851b8d 100644
--- a/app/main.c
+++ b/app/main.c
@@ -1197,5 +1197,20 @@ gimp_init_i18n (void)
   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
 #endif
 
+#ifdef HAVE_ISO_CODES
+  /* This iso-codes domain is the only external text domain our core
+   * code is using. Let's make usre it's properly initialized.
+   */
+#ifdef ENABLE_RELOCATABLE_RESOURCES
+  gimp_bind_text_domain ("iso_639_3", gimp_locale_directory ());
+#else
+  gimp_bind_text_domain ("iso_639_3", ISOCODES_LOCALEDIR);
+#endif
+
+#ifdef HAVE_BIND_TEXTDOMAIN_CODESET
+  bind_textdomain_codeset ("iso_639_3", "UTF-8");
+#endif
+#endif
+
   textdomain (GETTEXT_PACKAGE);
 }
diff --git a/meson.build b/meson.build
index c49e2bd253..f3860b698b 100644
--- a/meson.build
+++ b/meson.build
@@ -1184,6 +1184,7 @@ if isocodes.found()
   isocodes_prefix = isocodes.get_variable(pkgconfig: 'prefix')
   isocodes_location = isocodes_prefix / 'share' / 'xml' / 'iso-codes'
   isocodes_localedir= isocodes_prefix / 'share' / 'locale'
+  conf.set_quoted('ISOCODES_LOCALEDIR', isocodes_localedir)
 endif
 conf.set('HAVE_ISO_CODES', isocodes.found())
 
diff --git a/tools/meson.build b/tools/meson.build
index e7b32cd6b0..6a39f71c8f 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -39,7 +39,6 @@ if isocodes.found()
                              dependencies: [ native_gio ],
                              c_args: [
                                '-DSRCDIR="@0@"'.format(meson.project_source_root()),
-                               '-DISOCODES_LOCALEDIR="@0@"'.format(isocodes_localedir),
                              ],
                              native: true,
                              install: false)