diff --git a/glib/tests/fileutils.c b/glib/tests/fileutils.c
index 8868d11dc..56be80404 100644
--- a/glib/tests/fileutils.c
+++ b/glib/tests/fileutils.c
@@ -1486,8 +1486,11 @@ resize_file (const gchar *filename,
 
 #ifdef G_OS_WIN32
   retval = _chsize_s (fd, size);
-#else
+#elif HAVE_FTRUNCATE64
   retval = ftruncate64 (fd, size);
+#else
+  errno = ENOSYS;
+  retval = -1;
 #endif
   if (retval != 0)
     {
diff --git a/meson.build b/meson.build
index 2b6f394c7..d48f13903 100644
--- a/meson.build
+++ b/meson.build
@@ -646,6 +646,7 @@ functions = [
   'free_aligned_sized',
   'free_sized',
   'fsync',
+  'ftruncate64',
   'getauxval',
   'getc_unlocked',
   'getfsstat',