diff --git a/crashelper/include/backward.hpp b/crashelper/include/backward.hpp
index d781558..35896e5 100644
--- a/crashelper/include/backward.hpp
+++ b/crashelper/include/backward.hpp
@@ -28,6 +28,8 @@
 #error "It's not going to compile without a C++ compiler..."
 #endif
 
+#include <functional>
+
 #if defined(BACKWARD_CXX11)
 #elif defined(BACKWARD_CXX98)
 #else