diff --git a/lib/base/tlsutility.cpp b/lib/base/tlsutility.cpp
index 3c6751002..498feed7a 100644
--- a/lib/base/tlsutility.cpp
+++ b/lib/base/tlsutility.cpp
@@ -809,19 +809,4 @@ bool VerifyCertificate(const std::shared_ptr<X509>& caCertificate, const std::sh
 	return rc == 1;
 }
 
-std::string to_string(const errinfo_openssl_error& e)
-{
-	std::ostringstream tmp;
-	int code = e.value();
-	char errbuf[120];
-
-	const char *message = ERR_error_string(code, errbuf);
-
-	if (!message)
-		message = "Unknown error.";
-
-	tmp << code << ", \"" << message << "\"";
-	return "[errinfo_openssl_error]" + tmp.str() + "\n";
-}
-
 }
diff --git a/lib/base/tlsutility.hpp b/lib/base/tlsutility.hpp
index de7033311..ac4e642b6 100644
--- a/lib/base/tlsutility.hpp
+++ b/lib/base/tlsutility.hpp
@@ -52,8 +52,6 @@ class openssl_error : virtual public std::exception, virtual public boost::excep
 struct errinfo_openssl_error_;
 typedef boost::error_info<struct errinfo_openssl_error_, unsigned long> errinfo_openssl_error;
 
-std::string to_string(const errinfo_openssl_error& e);
-
 }
 
 #endif /* TLSUTILITY_H */