diff --git a/library/include/mobilisis/calculate_price.h b/library/include/mobilisis/calculate_price.h
index ee5f1e9..83484b1 100644
--- a/library/include/mobilisis/calculate_price.h
+++ b/library/include/mobilisis/calculate_price.h
@@ -90,9 +90,9 @@ struct CALCULATE_LIBRARY_API CalcState {
         , m_desc(desc) {
     }
 
-    explicit CalcState(State state, QString desc = "",
-                       QTime const &from = QTime(),
-                       QTime const &until = QTime())
+    explicit CalcState(State state, QString desc,
+                       QTime const &from,
+                       QTime const &until)
         : m_status(state)
         , m_desc(desc)
         , m_allowedTimeRange(from, until) {