diff --git a/lib/hcrypto/evp-pkcs11.c b/lib/hcrypto/evp-pkcs11.c
index 75bfee6a1..5c1bc6c18 100644
--- a/lib/hcrypto/evp-pkcs11.c
+++ b/lib/hcrypto/evp-pkcs11.c
@@ -763,7 +763,7 @@ PKCS11_CIPHER_ALGORITHM(rc4_40,
 
 PKCS11_MD_ALGORITHM(md2,    CKM_MD2,    16, 16)
 #ifdef CKM_MD4 /* non-standard extension */
-PKCS11_MD_ALGORITHM(md4,    CKM_MD4,    16, 16)
+PKCS11_MD_ALGORITHM(md4,    CKM_MD4,    16, 64)
 #else
 PKCS11_MD_ALGORITHM_UNAVAILABLE(md4)
 #endif