diff --git a/glib/glibconfig.h.in b/glib/glibconfig.h.in
index 0d533c9f7..4e018a5f1 100644
--- a/glib/glibconfig.h.in
+++ b/glib/glibconfig.h.in
@@ -212,6 +212,8 @@ typedef @g_pid_type@ GPid;
 #define G_SEARCHPATH_SEPARATOR '@g_searchpath_separator@'
 #define G_SEARCHPATH_SEPARATOR_S "@g_searchpath_separator@"
 
+#mesondefine G_HAVE_FREE_SIZED
+
 G_END_DECLS
 
 #endif /* __GLIBCONFIG_H__ */
diff --git a/glib/gmem.h b/glib/gmem.h
index 6e9b8ae16..9f3d42733 100644
--- a/glib/gmem.h
+++ b/glib/gmem.h
@@ -166,13 +166,13 @@ void     g_aligned_free_sized (gpointer  mem,
 #endif /* __GNUC__ */
 
 
-#if G_GNUC_CHECK_VERSION (4, 1) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78
+#if G_GNUC_CHECK_VERSION (4, 1) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78 && defined(G_HAVE_FREE_SIZED)
 
 #define g_free(mem)                                                            \
   (__builtin_object_size ((mem), 0) != ((size_t) - 1)) ?                       \
     g_free_sized (mem, __builtin_object_size ((mem), 0)) : (g_free) (mem)
 
-#endif /* G_GNUC_CHECK_VERSION (4, 1) && && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78 */
+#endif /* G_GNUC_CHECK_VERSION (4, 1) && && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78 && defined(G_HAVE_FREE_SIZED) */
 
 /**
  * g_steal_pointer:
diff --git a/meson.build b/meson.build
index 1d3754abb..1c62ea352 100644
--- a/meson.build
+++ b/meson.build
@@ -729,6 +729,10 @@ foreach f : functions
   endif
 endforeach
 
+# Export the information about free_sized() so we can correctly define a macro
+# wrapper around g_free()/g_free_sized() depending on whether it’s available
+glibconfig_conf.set('G_HAVE_FREE_SIZED', have_func_free_sized)
+
 # Check that stpcpy() is usable; must use header.
 # See:
 # https://github.com/mesonbuild/meson/issues/5628.