diff --git a/library/include/mobilisis/calculate_price.h b/library/include/mobilisis/calculate_price.h
index 0be6547..5f05367 100644
--- a/library/include/mobilisis/calculate_price.h
+++ b/library/include/mobilisis/calculate_price.h
@@ -22,7 +22,7 @@ typedef Configuration parking_tariff_t;
 extern "C" {
 #endif
 
-struct price_t {
+struct CALCULATE_LIBRARY_API price_t {
     uint32_t units;
     double netto;
     double brutto;