diff --git a/contrib/hstore/README.hstore b/contrib/hstore/README.hstore
index 601ae49259d7c46d836bb3227dd56416689be6ad..5fdceb1b986d4c30169a511de94e05c3b07af74e 100644
--- a/contrib/hstore/README.hstore
+++ b/contrib/hstore/README.hstore
@@ -117,20 +117,20 @@ regression=# select * from each('a=>1,b=>2');
  a   | 1
  b   | 2
 
-    * isexists (hstore,text) - returns 'true if key is exists in hstore and 
+    * exist (hstore,text) - returns 'true if key is exists in hstore and 
 	false otherwise. 
 
-regression=# select isexists('a=>1','a');
- isexists 
+regression=# select exist('a=>1','a');
+ exist 
 ----------
  t
 
-    * isdefined (hstore,text) - returns true if key is exists in hstore and 
+    * defined (hstore,text) - returns true if key is exists in hstore and 
 	  its value is not NULL. 
 
-regression=# select isdefined('a=>NULL','a');
- isdefined 
------------
+regression=# select defined('a=>NULL','a');
+ defined 
+---------
  f
 
 Indices
diff --git a/contrib/hstore/expected/hstore.out b/contrib/hstore/expected/hstore.out
index 61c96a4b976b9b0b4bcfd7adb997c6107455ac5b..94194a6d00b91381e51d5145a9023fbb92aacd4c 100644
--- a/contrib/hstore/expected/hstore.out
+++ b/contrib/hstore/expected/hstore.out
@@ -273,39 +273,39 @@ select ('aa=>NULL, c=>d , b=>16'::hstore->'aa') is null;
 (1 row)
 
 -- exists/defined
-select isexists('a=>NULL, b=>qq', 'a');
- isexists 
-----------
+select exist('a=>NULL, b=>qq', 'a');
+ exist 
+-------
  t
 (1 row)
 
-select isexists('a=>NULL, b=>qq', 'b');
- isexists 
-----------
+select exist('a=>NULL, b=>qq', 'b');
+ exist 
+-------
  t
 (1 row)
 
-select isexists('a=>NULL, b=>qq', 'c');
- isexists 
-----------
+select exist('a=>NULL, b=>qq', 'c');
+ exist 
+-------
  f
 (1 row)
 
-select isdefined('a=>NULL, b=>qq', 'a');
- isdefined 
------------
+select defined('a=>NULL, b=>qq', 'a');
+ defined 
+---------
  f
 (1 row)
 
-select isdefined('a=>NULL, b=>qq', 'b');
- isdefined 
------------
+select defined('a=>NULL, b=>qq', 'b');
+ defined 
+---------
  t
 (1 row)
 
-select isdefined('a=>NULL, b=>qq', 'c');
- isdefined 
------------
+select defined('a=>NULL, b=>qq', 'c');
+ defined 
+---------
  f
 (1 row)
 
diff --git a/contrib/hstore/hstore.sql.in b/contrib/hstore/hstore.sql.in
index c77fc7d4fb6162edf79ebf3f7cd72ecfa4f9026c..95cecf15d29c95b08f95733f39d11bfe5147cf93 100644
--- a/contrib/hstore/hstore.sql.in
+++ b/contrib/hstore/hstore.sql.in
@@ -35,11 +35,21 @@ RETURNS bool
 AS 'MODULE_PATHNAME','exists'
 LANGUAGE 'C' with (isstrict,iscachable);
 
+CREATE FUNCTION exist(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','exists'
+LANGUAGE 'C' with (isstrict,iscachable);
+
 CREATE FUNCTION isdefined(hstore,text)
 RETURNS bool
 AS 'MODULE_PATHNAME','defined'
 LANGUAGE 'C' with (isstrict,iscachable);
 
+CREATE FUNCTION defined(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','defined'
+LANGUAGE 'C' with (isstrict,iscachable);
+
 CREATE FUNCTION delete(hstore,text)
 RETURNS hstore
 AS 'MODULE_PATHNAME','delete'
diff --git a/contrib/hstore/sql/hstore.sql b/contrib/hstore/sql/hstore.sql
index 0931616077b7573ffff62f168fdb0beeb2a31f98..f268da557c8e80dbfd8968c9ecda2c1d7e6af244 100644
--- a/contrib/hstore/sql/hstore.sql
+++ b/contrib/hstore/sql/hstore.sql
@@ -66,12 +66,12 @@ select ('aa=>NULL, c=>d , b=>16'::hstore->'aa') is null;
 
 -- exists/defined
 
-select isexists('a=>NULL, b=>qq', 'a');
-select isexists('a=>NULL, b=>qq', 'b');
-select isexists('a=>NULL, b=>qq', 'c');
-select isdefined('a=>NULL, b=>qq', 'a');
-select isdefined('a=>NULL, b=>qq', 'b');
-select isdefined('a=>NULL, b=>qq', 'c');
+select exist('a=>NULL, b=>qq', 'a');
+select exist('a=>NULL, b=>qq', 'b');
+select exist('a=>NULL, b=>qq', 'c');
+select defined('a=>NULL, b=>qq', 'a');
+select defined('a=>NULL, b=>qq', 'b');
+select defined('a=>NULL, b=>qq', 'c');
 
 -- delete 
 
diff --git a/contrib/hstore/uninstall_hstore.sql b/contrib/hstore/uninstall_hstore.sql
index 153337ccb0b142a4eff6a7fe57df91ed39b657d4..bfa2e738dce2ffcddaba5c99c723b82fc34b8028 100644
--- a/contrib/hstore/uninstall_hstore.sql
+++ b/contrib/hstore/uninstall_hstore.sql
@@ -13,7 +13,9 @@ DROP OPERATOR =>( text, text );
 
 DROP FUNCTION fetchval(hstore,text);
 DROP FUNCTION isexists(hstore,text);
+DROP FUNCTION exist(hstore,text);
 DROP FUNCTION isdefined(hstore,text);
+DROP FUNCTION defined(hstore,text);
 DROP FUNCTION delete(hstore,text);
 DROP FUNCTION hs_concat(hstore,hstore);
 DROP FUNCTION hs_contains(hstore,hstore);