diff --git a/src/postgresqlconnector.cpp b/src/postgresqlconnector.cpp
index 37acfac..4a31f89 100644
--- a/src/postgresqlconnector.cpp
+++ b/src/postgresqlconnector.cpp
@@ -560,7 +560,7 @@ void PostgreSQLConnector::log_unsupported_bin_format()
 
 
 
-size_t PostgreSQLConnector::unescape_bin_char(const char * str, wchar_t & field_value, FT field_type)
+size_t PostgreSQLConnector::unescape_bin_char(const char * str, wchar_t & field_value, const FT & field_type)
 {
 	if( str[0]!='\\' || str[1]!='x' )
 	{
@@ -588,7 +588,7 @@ void PostgreSQLConnector::unescape_bin_string(const char * str, std::string & ou
 }
 
 
-void PostgreSQLConnector::unescape_bin_string(const char * str, std::wstring & out, FT field_type)
+void PostgreSQLConnector::unescape_bin_string(const char * str, std::wstring & out, const FT & field_type)
 {
 	if( str[0]!='\\' || str[1]!='x' )
 	{
diff --git a/src/postgresqlconnector.h b/src/postgresqlconnector.h
index 9403d9f..0f771d1 100644
--- a/src/postgresqlconnector.h
+++ b/src/postgresqlconnector.h
@@ -100,9 +100,9 @@ protected:
 
 	void log_unsupported_bin_format();
 
-	size_t unescape_bin_char(const char * str, wchar_t & field_value, FT field_type);
+	size_t unescape_bin_char(const char * str, wchar_t & field_value, const FT & field_type);
 	void unescape_bin_string(const char * str, std::string & out);
-	void unescape_bin_string(const char * str, std::wstring & out, FT field_type);
+	void unescape_bin_string(const char * str, std::wstring & out, const FT & field_type);
 
 };