diff --git a/README.md b/README.md
index 55345ab1..6411d7a6 100644
--- a/README.md
+++ b/README.md
@@ -478,7 +478,7 @@ Returns a table containing the `parameters` of pkey instance.
 
 **syntax**: *ok, err = pk:set_parameters(params)*
 
-Set the paramets of the pkey from a table `params`.
+Set the parameters of the pkey from a table `params`.
 If the parameter is not set in the `params` table,
 it remains untouched in the pkey instance.
 
diff --git a/lib/resty/openssl/digest.lua b/lib/resty/openssl/digest.lua
index da117e0f..938d614c 100644
--- a/lib/resty/openssl/digest.lua
+++ b/lib/resty/openssl/digest.lua
@@ -1,7 +1,6 @@
 local ffi = require "ffi"
 local C = ffi.C
 local ffi_gc = ffi.gc
-local ffi_new = ffi.new
 local ffi_str = ffi.string
 
 require "resty.openssl.include.evp"
diff --git a/lib/resty/openssl/pkey.lua b/lib/resty/openssl/pkey.lua
index 4a34a951..86e0596a 100644
--- a/lib/resty/openssl/pkey.lua
+++ b/lib/resty/openssl/pkey.lua
@@ -553,7 +553,7 @@ function _M:verify(signature, digest)
     end
     ffi_gc(md_ctx, C.EVP_MD_CTX_free)
     if C.EVP_DigestVerifyInit(md_ctx, nil, nil, nil, self.ctx) ~= 1 then
-      return nil, format_error("pkey:verify: EVP_DigestSignInit")
+      return nil, format_error("pkey:verify: EVP_DigestVerifyInit")
     end
     code = C.EVP_DigestVerify(md_ctx, signature, #signature, digest, #digest)
   end
diff --git a/lib/resty/openssl/provider.lua b/lib/resty/openssl/provider.lua
index 811d28c3..e910215a 100644
--- a/lib/resty/openssl/provider.lua
+++ b/lib/resty/openssl/provider.lua
@@ -1,9 +1,5 @@
 local ffi = require "ffi"
 local C = ffi.C
-local ffi_gc = ffi.gc
-local ffi_new = ffi.new
-local ffi_str = ffi.string
-local ffi_cast = ffi.cast
 
 require "resty.openssl.include.provider"
 local OPENSSL_30 = require("resty.openssl.version").OPENSSL_30