diff --git a/lib/resty/evp.lua b/lib/resty/evp.lua
index 40c4545..01b8d61 100644
--- a/lib/resty/evp.lua
+++ b/lib/resty/evp.lua
@@ -27,7 +27,7 @@ local CONST = {
     EVP_PKEY_ALG_CTRL = 0x1000,
     EVP_PKEY_CTRL_RSA_PADDING = 0x1000 + 1,
 
-    EVP_PKEY_OP_TYPE_CRYPT = 768,
+    EVP_PKEY_OP_TYPE_CRYPT = 1536,
     EVP_PKEY_CTRL_RSA_OAEP_MD = 0x1000 + 9
 }
 _M.CONST = CONST