diff --git a/src/A3.cpp b/src/A3.cpp
index 20a1a1945..7d1294c9d 100644
--- a/src/A3.cpp
+++ b/src/A3.cpp
@@ -25,6 +25,9 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 #include <cmake.h>
+#ifdef FEATURE_STDIN
+#include <iostream>
+#endif
 #include <sstream>
 #include <algorithm>
 #include <stdlib.h>