diff --git a/src/sim/main.cc b/src/sim/main.cc
index e7fb4039eb..0341b7d5f0 100644
--- a/src/sim/main.cc
+++ b/src/sim/main.cc
@@ -29,6 +29,7 @@
  */
 
 #include <Python.h>
+#include <signal.h>
 
 #include <iostream>
 #include <string>