diff --git a/contrib/cube/cube.sql.in b/contrib/cube/cube.sql.in
index 5aadf7ba1bbb9900d4fc45334b88c15c29317abd..60ac7d8aee022644f1dee22c0b4770d317ad404a 100644
--- a/contrib/cube/cube.sql.in
+++ b/contrib/cube/cube.sql.in
@@ -32,6 +32,8 @@ LANGUAGE 'C' IMMUTABLE STRICT;
 
 COMMENT ON FUNCTION cube(text) IS 'convert text to cube';
 
+CREATE CAST (text AS cube) WITH FUNCTION cube(text) AS ASSIGNMENT;
+
 --
 -- External C-functions for R-tree methods
 --