diff --git a/greeter/seccomp_filter.cpp b/greeter/seccomp_filter.cpp
--- a/greeter/seccomp_filter.cpp
+++ b/greeter/seccomp_filter.cpp
@@ -32,6 +32,7 @@
 #include <seccomp.h>
 #include <sys/socket.h>
 #include <fcntl.h>
+#include <errno.h>
 
 namespace ScreenLocker
 {