diff --git a/lib/config-win32.h b/lib/config-win32.h
index ba3e7a708..95f1595be 100644
--- a/lib/config-win32.h
+++ b/lib/config-win32.h
@@ -700,7 +700,9 @@
 #endif
 
 /* Define to use the Windows crypto library. */
+#if !defined(USE_SSLEAY) && !defined(USE_NSS)
 #define USE_WIN32_CRYPTO
+#endif
 
 /* ---------------------------------------------------------------- */
 /*                       ADDITIONAL DEFINITIONS                     */