diff --git a/src/libwolfboot.c b/src/libwolfboot.c
index 40ba5e0e78..db414f23bf 100644
--- a/src/libwolfboot.c
+++ b/src/libwolfboot.c
@@ -156,7 +156,8 @@ int wolfBoot_initialize_encryption(void)
     /* MAGIC (4B) + PART_FLAG (1B) */
 #endif /* EXT_FLASH && EXT_ENCRYPTED */
 
-#if !defined(__WOLFBOOT) && !defined(UNIT_TEST)
+#if !defined(__WOLFBOOT) && !defined(UNIT_TEST) && \
+    (!defined(EXT_ENCRYPTED) || defined(BUILD_TOOL))
     /* Avoid redefining if already defined by wolfSSL headers */
     #if !defined(XMEMSET)
         #define XMEMSET memset