diff --git a/include/jwt/error_codes.hpp b/include/jwt/error_codes.hpp
index 6b63a9b..13af452 100644
--- a/include/jwt/error_codes.hpp
+++ b/include/jwt/error_codes.hpp
@@ -11,6 +11,7 @@ enum class AlgorithmErrc
 {
   SigningErr = 1,
   VerificationErr,
+  KeyNotFoundErr,
   NoneAlgorithmUsed, // Not an actual error!
 };
 
diff --git a/include/jwt/impl/error_codes.ipp b/include/jwt/impl/error_codes.ipp
index d3bda2d..a1ad64a 100644
--- a/include/jwt/impl/error_codes.ipp
+++ b/include/jwt/impl/error_codes.ipp
@@ -22,6 +22,8 @@ struct AlgorithmErrCategory: std::error_category
       return "signing failed";
     case AlgorithmErrc::VerificationErr:
       return "verification failed";
+    case AlgorithmErrc::KeyNotFoundErr:
+      return "key not provided";
     case AlgorithmErrc::NoneAlgorithmUsed:
       return "none algorithm used";
     };
diff --git a/include/jwt/impl/jwt.ipp b/include/jwt/impl/jwt.ipp
index 500e282..f85f8f5 100644
--- a/include/jwt/impl/jwt.ipp
+++ b/include/jwt/impl/jwt.ipp
@@ -338,6 +338,15 @@ jwt_object& jwt_object::remove_claim(const string_view name)
 std::string jwt_object::signature(std::error_code& ec) const
 {
   ec.clear();
+
+  //key/secret should be set for any algorithm except NONE
+  if (header().algo() != jwt::algorithm::NONE) {
+    if (secret_.length() == 0) {
+      ec = AlgorithmErrc::KeyNotFoundErr;
+      return {};
+    }
+  }
+
   jwt_signature jws{secret_};
   return jws.encode(header_, payload_, ec);
 }
diff --git a/tests/test_jwt_encode b/tests/test_jwt_encode
index 18266aa..0b412ca 100755
Binary files a/tests/test_jwt_encode and b/tests/test_jwt_encode differ
diff --git a/tests/test_jwt_encode.cc b/tests/test_jwt_encode.cc
index fdda646..396c2e3 100644
--- a/tests/test_jwt_encode.cc
+++ b/tests/test_jwt_encode.cc
@@ -138,9 +138,7 @@ TEST (EncodeTest, StrEncodeHS512WithKey)
 
   jwt::string_view key = "00112233445566778899";
 
-  //TODO: map of jwt::string_view not working
-
-  std::map<std::string, std::string> p;
+  std::map<jwt::string_view, jwt::string_view> p;
   p["aud"] = "rift.io";
   p["sub"] = "nothing much";
 
@@ -180,6 +178,43 @@ TEST (EncodeTest, StrEncodeChangeAlg)
   EXPECT_EQ (expected_none_sign, enc_str);
 }
 
+TEST (EncodeTest, StrEncodeNoKey)
+{
+  using namespace jwt::params;
+
+  jwt::jwt_object obj{algorithm(jwt::algorithm::HS512),
+                      payload({{"iss", "arn-ml"}})
+                      };
+
+  std::error_code ec;
+  std::string enc_str = obj.signature(ec);
+
+  ASSERT_TRUE (ec);
+  EXPECT_EQ (ec.value(), static_cast<int>(jwt::AlgorithmErrc::KeyNotFoundErr));
+}
+
+TEST (EncodeTest, StrEncodeNoneAlgWithKey)
+{
+  using namespace jwt::params;
+
+  const jwt::string_view secret1 = "abcdefghijklmnopqrstuvwxyz";
+  const jwt::string_view secret2 = "0123456789qwertybabe";
+
+  jwt::jwt_object obj{algorithm("NONE"),
+                      payload({{"iss", "arn-ml"}}),
+                      secret(secret1)};
+
+  std::error_code ec;
+  std::string enc_str1 = obj.signature(ec);
+  ASSERT_FALSE (ec);
+
+  obj.secret(secret2);
+  std::string enc_str2 = obj.signature(ec);
+  ASSERT_FALSE (ec);
+
+  EXPECT_EQ (enc_str1, enc_str2);
+}
+
 int main(int argc, char **argv) 
 {
   ::testing::InitGoogleTest(&argc, argv);