Fix type definition of triq_dom:domrec/1
diff --git a/src/triq_dom.erl b/src/triq_dom.erl
index e74a3a2..e35f5b7 100644
--- a/src/triq_dom.erl
+++ b/src/triq_dom.erl
@@ -58,6 +58,7 @@
                     atom() | tuple(),
                     pick_fun(T),
                     shrink_fun(T),
+                    boolean(),
                     boolean()}.
 
 -define(BOX,'@box').