diff --git a/include/sta/Property.hh b/include/sta/Property.hh
index 93b34e32..7e19b15c 100644
--- a/include/sta/Property.hh
+++ b/include/sta/Property.hh
@@ -26,6 +26,7 @@
 
 #include <map>
 #include <string>
+#include <functional>
 
 #include "LibertyClass.hh"
 #include "NetworkClass.hh"