diff --git a/library/include/mobilisis/utilities.h b/library/include/mobilisis/utilities.h
index d47ee5e..cf1b756 100644
--- a/library/include/mobilisis/utilities.h
+++ b/library/include/mobilisis/utilities.h
@@ -79,12 +79,12 @@ namespace Utilities {
 	double CalculatePricePerUnit(double pra_price, double durationUnit = -1);
 
     QTime SpecialDaysWorkTimeFrom(Configuration const *cfg, int specialDayId);
-    QTime SpecialDaysWorkTimeFrom(Configuration::SpecialDaysWorktimeType::const_iterator it);
+    QTime SpecialDaysWorkTimeFrom(Configuration::SpecialDaysWorktimeType::const_iterator const &it);
     QTime SpecialDaysWorkTimeUntil(Configuration const *cfg, int specialDayId);
-    QTime SpecialDaysWorkTimeUntil(Configuration::SpecialDaysWorktimeType::const_iterator it);
-    QTime WeekDaysWorkTimeFrom(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr);
-    QTime WeekDaysWorkTimeUntil(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr);
-    int WeekDayId(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr);
+    QTime SpecialDaysWorkTimeUntil(Configuration::SpecialDaysWorktimeType::const_iterator const &it);
+    QTime WeekDaysWorkTimeFrom(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr);
+    QTime WeekDaysWorkTimeUntil(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr);
+    int WeekDayId(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr);
     // PaymentRate GetPaymentRate(Configuration const *cfg, );
     bool isCarryOverSet(Configuration const *cfg, PaymentMethod paymentMethodId);
     bool isCarryOverNotSet(Configuration const *cfg, PaymentMethod paymentMethodId);
diff --git a/library/src/utilities.cpp b/library/src/utilities.cpp
index 28a2306..ff47fc5 100644
--- a/library/src/utilities.cpp
+++ b/library/src/utilities.cpp
@@ -334,11 +334,11 @@ QTime Utilities::SpecialDaysWorkTimeFrom(Configuration const *cfg, int specialDa
     return QTime::fromString(cfg->SpecialDaysWorktime.find(specialDayId)->second.pedwt_time_from.c_str(), Qt::ISODate);
 }
 
-QTime Utilities::SpecialDaysWorkTimeFrom(Configuration::SpecialDaysWorktimeType::const_iterator it) {
+QTime Utilities::SpecialDaysWorkTimeFrom(Configuration::SpecialDaysWorktimeType::const_iterator const &it) {
     return QTime::fromString(it->second.pedwt_time_from.c_str(), Qt::ISODate);
 }
 
-QTime Utilities::SpecialDaysWorkTimeUntil(Configuration::SpecialDaysWorktimeType::const_iterator it) {
+QTime Utilities::SpecialDaysWorkTimeUntil(Configuration::SpecialDaysWorktimeType::const_iterator const &it) {
     return QTime::fromString(it->second.pedwt_time_to.c_str(), Qt::ISODate);
 }
 
@@ -346,15 +346,15 @@ QTime Utilities::SpecialDaysWorkTimeUntil(Configuration const *cfg, int specialD
     return QTime::fromString(cfg->SpecialDaysWorktime.find(specialDayId)->second.pedwt_time_to.c_str(), Qt::ISODate);
 }
 
-QTime Utilities::WeekDaysWorkTimeFrom(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr) {
+QTime Utilities::WeekDaysWorkTimeFrom(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr) {
     return QTime::fromString(itr->second.pwd_time_from.c_str(), Qt::ISODate);
 }
 
-QTime Utilities::WeekDaysWorkTimeUntil(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr) {
+QTime Utilities::WeekDaysWorkTimeUntil(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr) {
     return QTime::fromString(itr->second.pwd_time_to.c_str(), Qt::ISODate);
 }
 
-int Utilities::WeekDayId(std::multimap<int, ATBWeekDaysWorktime>::const_iterator itr) {
+int Utilities::WeekDayId(std::multimap<int, ATBWeekDaysWorktime>::const_iterator const &itr) {
     return itr->second.pwd_period_day_in_week_id;
 }