diff --git a/packages/clib/process.pl b/packages/clib/process.pl
index 0dfe35652..0e600a9eb 100644
--- a/packages/clib/process.pl
+++ b/packages/clib/process.pl
@@ -43,6 +43,7 @@
 :- use_module(library(shlib)).
 :- use_module(library(lists)).
 :- use_module(library(option)).
+:- use_module(library(error)).
 
 :- use_foreign_library(foreign(process)).