diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index 099dc059b..806e256e0 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -31643,7 +31643,7 @@ int wc_SetExtKeyUsageOID(Cert *cert, const char *in, word32 sz, byte idx,
         void* heap)
 {
     byte oid[MAX_OID_SZ];
-    word32 oidSz = MAX_OID_SZ;
+    word32 oidSz = CTC_MAX_EKU_OID_SZ;
 
     if (idx >= CTC_MAX_EKU_NB || sz >= CTC_MAX_EKU_OID_SZ) {
         WOLFSSL_MSG("Either idx or sz was too large");