diff --git a/src/cpp/session/modules/SessionHistoryArchive.hpp.orig b/src/cpp/session/modules/SessionHistoryArchive.hpp
index 3f17c00..96f3095 100644
--- a/src/cpp/session/modules/SessionHistoryArchive.hpp.orig
+++ b/src/cpp/session/modules/SessionHistoryArchive.hpp
@@ -20,6 +20,7 @@
 #include <vector>
 
 #include <boost/utility.hpp>
+#include <ctime>
 
 namespace rstudio {
 namespace core {
