diff --git a/config.h.meson b/config.h.meson
index 73836bb9ee..54dec7fa82 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -293,3 +293,5 @@
 #mesondefine HAVE_HARFBUZZ
 
 #mesondefine HAVE_PANGOFT
+
+#mesondefine ISO_CODES_PREFIX
diff --git a/demos/gtk-demo/language-names.c b/demos/gtk-demo/language-names.c
index 2d433cff06..0c0076bbd8 100644
--- a/demos/gtk-demo/language-names.c
+++ b/demos/gtk-demo/language-names.c
@@ -17,7 +17,6 @@
 
 #include "language-names.h"
 
-#define ISO_CODES_PREFIX "/usr"
 #define ISO_CODES_DATADIR ISO_CODES_PREFIX "/share/xml/iso-codes"
 #define ISO_CODES_LOCALESDIR ISO_CODES_PREFIX "/share/locale"
 
diff --git a/gtk/language-names.c b/gtk/language-names.c
index 2d433cff06..0c0076bbd8 100644
--- a/gtk/language-names.c
+++ b/gtk/language-names.c
@@ -17,7 +17,6 @@
 
 #include "language-names.h"
 
-#define ISO_CODES_PREFIX "/usr"
 #define ISO_CODES_DATADIR ISO_CODES_PREFIX "/share/xml/iso-codes"
 #define ISO_CODES_LOCALESDIR ISO_CODES_PREFIX "/share/locale"
 
diff --git a/meson.build b/meson.build
index 64c73e4a01..2b189db816 100644
--- a/meson.build
+++ b/meson.build
@@ -336,6 +336,7 @@ harfbuzz_dep   = dependency('harfbuzz', version: '>= 0.9', required: false)
 xkbdep         = dependency('xkbcommon', version: xkbcommon_req, required: wayland_enabled)
 graphene_dep   = dependency('graphene-gobject-1.0', version: graphene_req,
                             fallback: ['graphene', 'graphene_dep'])
+iso_codes_dep  = dependency('iso-codes', required: false)
 
 fontconfig_dep = [] # only used in x11 backend
 atkbridge_dep  = [] # only used in x11 backend
@@ -349,6 +350,12 @@ endif
 cdata.set('HAVE_HARFBUZZ', harfbuzz_dep.found())
 cdata.set('HAVE_PANGOFT', pangoft_dep.found())
 
+if iso_codes_dep.found()
+  cdata.set_quoted('ISO_CODES_PREFIX', iso_codes_dep.get_pkgconfig_variable('prefix'))
+else
+  cdata.set_quoted('ISO_CODES_PREFIX', '/usr')
+endif
+
 backend_immodules = []
 
 pc_gdk_extra_libs = []