diff --git a/src/libutil/error.hh b/src/libutil/error.hh
index 2ba3a3b33..1e6102ce1 100644
--- a/src/libutil/error.hh
+++ b/src/libutil/error.hh
@@ -4,6 +4,7 @@
 #include "ref.hh"
 #include "types.hh"
 
+#include <cstring>
 #include <list>
 #include <memory>
 #include <map>