diff --git a/test/chrono-test.cc b/test/chrono-test.cc
index 33353ca8..c218a873 100644
--- a/test/chrono-test.cc
+++ b/test/chrono-test.cc
@@ -456,7 +456,7 @@ TEST(chrono_test, format_default) {
             fmt::format("{}", std::chrono::duration<int, std::exa>(42)));
   EXPECT_EQ("42min", fmt::format("{}", std::chrono::minutes(42)));
   EXPECT_EQ("42h", fmt::format("{}", std::chrono::hours(42)));
-#  if __cpp_lib_chrono >= 201907L
+#  if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907L
   EXPECT_EQ("42d", fmt::format("{}", std::chrono::days(42)));
 #  endif
   EXPECT_EQ(