diff --git a/src/api/api_solver.cpp b/src/api/api_solver.cpp
index 42c364cd6..2de51c3b0 100644
--- a/src/api/api_solver.cpp
+++ b/src/api/api_solver.cpp
@@ -17,6 +17,7 @@ Revision History:
 
 --*/
 #include<iostream>
+#include<thread>
 #include "util/scoped_ctrl_c.h"
 #include "util/cancel_eh.h"
 #include "util/file_path.h"