diff --git a/wolfssl/internal.h b/wolfssl/internal.h
index f2227a708..e3232e856 100644
--- a/wolfssl/internal.h
+++ b/wolfssl/internal.h
@@ -3490,10 +3490,6 @@ struct WOLFSSL_X509_NAME {
 #endif
 };
 
-#ifndef EXTERNAL_SERIAL_SIZE
-    #define EXTERNAL_SERIAL_SIZE 32
-#endif
-
 #ifdef NO_ASN
     typedef struct DNS_entry DNS_entry;
 #endif
diff --git a/wolfssl/wolfcrypt/asn.h b/wolfssl/wolfcrypt/asn.h
index 9f9b692e0..e2c4db31d 100644
--- a/wolfssl/wolfcrypt/asn.h
+++ b/wolfssl/wolfcrypt/asn.h
@@ -66,12 +66,14 @@
     extern "C" {
 #endif
 
+#ifndef EXTERNAL_SERIAL_SIZE
+    #define EXTERNAL_SERIAL_SIZE 32
+#endif
+
 enum {
     ISSUER  = 0,
     SUBJECT = 1,
 
-    EXTERNAL_SERIAL_SIZE = 32,
-
     BEFORE  = 0,
     AFTER   = 1
 };