diff --git a/cpp/ycm/IdentifierDatabase.h b/cpp/ycm/IdentifierDatabase.h
index 1f931ed4..c5cf6988 100644
--- a/cpp/ycm/IdentifierDatabase.h
+++ b/cpp/ycm/IdentifierDatabase.h
@@ -23,6 +23,7 @@
 #include <boost/thread/mutex.hpp>
 #include <boost/shared_ptr.hpp>
 
+#include <list>
 #include <vector>
 #include <string>