diff --git a/include/market_data.h b/include/market_data.h
index 87eb0b7..ac99a12 100644
--- a/include/market_data.h
+++ b/include/market_data.h
@@ -7,6 +7,7 @@
 #include <vector>
 #include <optional>
 #include <mutex>
+#include <memory>
 
 class StockData {
 public: