diff --git a/src/lib/library.c b/src/lib/library.c
index 6a4ae158..92efae9e 100644
--- a/src/lib/library.c
+++ b/src/lib/library.c
@@ -1,3 +1,4 @@
+#include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>