diff --git a/meson.build b/meson.build
index 11faabd..d82eefa 100644
--- a/meson.build
+++ b/meson.build
@@ -55,6 +55,11 @@ if cc.has_function('__fxstatat', prefix: '#include <sys/stat.h>')
   add_project_arguments('-DHAVE_FXSTATAT', language: 'c')
 endif
 
+# Not always explicit
+if cc.has_function('openat64', prefix: '#include <fcntl.h>')
+  add_project_arguments('-DHAVE_OPENAT64', language: 'c')
+endif
+
 meson.add_dist_script(srcdir / 'getversion.sh')
 
 #
diff --git a/tests/test-umockdev.c b/tests/test-umockdev.c
index 01ed911..bf6268a 100644
--- a/tests/test-umockdev.c
+++ b/tests/test-umockdev.c
@@ -1131,11 +1131,13 @@ t_testbed_libc(UMockdevTestbedFixture * fixture, UNUSED_DATA)
     g_assert_cmpint(fd, >=, 0);
     close(fd);
 
+#ifdef HAVE_OPENAT64
     fd = openat64(dirfd, "sys/devices/dev1/simple_attr", O_RDONLY);
     if (fd < 0)
         perror("openat64");
     g_assert_cmpint(fd, >=, 0);
     close(fd);
+#endif
 
     close(dirfd);
 
@@ -1146,7 +1148,7 @@ t_testbed_libc(UMockdevTestbedFixture * fixture, UNUSED_DATA)
     g_assert_cmpint(openat(dirfd, "sys", O_RDONLY), <, 0);
     g_assert_cmpint(errno, ==, ENOENT);
 
-    g_assert_cmpint(errno, ==, ENOENT);
+#ifdef HAVE_OPENAT64
     g_assert_cmpint(openat64(dirfd, "sys", O_RDONLY), <, 0);
     close(dirfd);
 
@@ -1154,6 +1156,7 @@ t_testbed_libc(UMockdevTestbedFixture * fixture, UNUSED_DATA)
     g_assert_cmpint(openat(AT_FDCWD, "sys/devices", O_RDONLY), <, 0);
     g_assert_cmpint(errno, ==, ENOENT);
     g_assert_cmpint(openat64(AT_FDCWD, "sys/devices", O_RDONLY), <, 0);
+#endif
 
     /* stat */
     g_assert_cmpint(stat ("/sys/bus/pci/devices", &st), ==, 0);