diff --git a/src/IcalComponent.hpp b/src/IcalComponent.hpp
index 1d4c394..aa06602 100644
--- a/src/IcalComponent.hpp
+++ b/src/IcalComponent.hpp
@@ -3,6 +3,8 @@
 
 #include "IcalDuration.hpp"
 #include "IcalTime.hpp"
+#include <string>
+#include <boost/shared_ptr.hpp>
 
 extern "C" {
 #include <libical/icalcomponent.h>
diff --git a/src/IcalDuration.hpp b/src/IcalDuration.hpp
index 1879f3f..5f0f147 100644
--- a/src/IcalDuration.hpp
+++ b/src/IcalDuration.hpp
@@ -1,6 +1,8 @@
 #ifndef __ICAL_DURATION_HPP__
 #define __ICAL_DURATION_HPP__
 
+#include <string>
+
 extern "C" {
 #include <libical/icalduration.h>
 }
diff --git a/src/Ics.cpp b/src/Ics.cpp
index a89388c..1a601fc 100644
--- a/src/Ics.cpp
+++ b/src/Ics.cpp
@@ -4,7 +4,9 @@
 #include "IcalParser.hpp"
 
 #include <iomanip>
+#include <iostream>
 #include <sstream>
+#include <memory>
 
 namespace fs = boost::filesystem;