diff --git a/tz.h b/tz.h
index 70c16d7..4d0789f 100644
--- a/tz.h
+++ b/tz.h
@@ -83,6 +83,8 @@ static_assert(HAS_REMOTE_API == 0 ? AUTO_DOWNLOAD == 0 : true,
 #      define MISSING_LEAP_SECONDS 0
 #    endif
 #  endif
+#else
+#  define MISSING_LEAP_SECONDS 0
 #endif
 
 #include "date.h"