diff --git a/library/x509_crt.c b/library/x509_crt.c
index 453389b..a784e63 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1540,6 +1540,7 @@
 {
     int ret = 0;
 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+#if _WIN32_WINNT >= 0x0501 /* _WIN32_WINNT_XP */
     int w_ret;
     WCHAR szDir[MAX_PATH];
     char filename[MAX_PATH];
@@ -1602,6 +1603,9 @@
 
 cleanup:
     FindClose(hFind);
+#else /* !_WIN32_WINNT_XP */
+#error mbedtls_x509_crt_parse_path not available before Windows XP
+#endif /* !_WIN32_WINNT_XP */
 #else /* _WIN32 */
     int t_ret;
     int snp_ret;