diff --git a/libi2pd/HTTP.cpp b/libi2pd/HTTP.cpp
index 08b0a8e4..036c1dde 100644
--- a/libi2pd/HTTP.cpp
+++ b/libi2pd/HTTP.cpp
@@ -230,7 +230,8 @@ namespace http
 		return true;
 	}
 
-	std::string URL::to_string() {
+	std::string URL::to_string() const
+	{
 		std::string out = "";
 		if (schema != "") {
 			out = schema + "://";
@@ -349,7 +350,7 @@ namespace http
 		return eoh + HTTP_EOH.length();
 	}
 
-	void HTTPReq::write(std::ostream & o)
+	void HTTPReq::write(std::ostream & o) const
 	{
 		o << method << " " << uri << " " << version << CRLF;
 		for (auto & h : headers)
@@ -357,7 +358,7 @@ namespace http
 		o << CRLF;
 	}
 
-	std::string HTTPReq::to_string()
+	std::string HTTPReq::to_string() const
 	{
 		std::stringstream ss;
 		write(ss);
diff --git a/libi2pd/HTTP.h b/libi2pd/HTTP.h
index 11e9df6e..ab6b4166 100644
--- a/libi2pd/HTTP.h
+++ b/libi2pd/HTTP.h
@@ -68,7 +68,7 @@ namespace http
 		 * @brief Serialize URL structure to url
 		 * @note Returns relative url if schema if empty, absolute url otherwise
 		 */
-		std::string to_string ();
+		std::string to_string () const;
 
 		/**
 		 * @brief return true if the host is inside i2p
@@ -107,8 +107,8 @@ namespace http
 		int parse(std::string_view buf);
 
 		/** @brief Serialize HTTP request to string */
-		std::string to_string();
-		void write(std::ostream & o);
+		std::string to_string() const;
+		void write(std::ostream & o) const;
 
 		void AddHeader (const std::string& name, const std::string& value);
 		void UpdateHeader (const std::string& name, const std::string& value);
@@ -151,8 +151,6 @@ namespace http
 		 */
 		std::string to_string();
 
-		void write(std::ostream & o);
-
 		/** @brief Checks that response declared as chunked data */
 		bool is_chunked() const ;