diff --git a/Makefile b/Makefile
index b2e76d7..a67f4fc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 EXTENSION = pgjwt
-DATA = pgjwt--0.1.0.sql
+DATA = pgjwt--0.1.1.sql pgjwt--0.1.0--0.1.1.sql
 
 # postgres build stuff
 PG_CONFIG = pg_config
diff --git a/pgjwt--0.1.0.sql b/pgjwt--0.1.0--0.1.1.sql
similarity index 96%
rename from pgjwt--0.1.0.sql
rename to pgjwt--0.1.0--0.1.1.sql
index 128a137..d726438 100644
--- a/pgjwt--0.1.0.sql
+++ b/pgjwt--0.1.0--0.1.1.sql
@@ -3,7 +3,7 @@
 
 CREATE OR REPLACE FUNCTION url_encode(data bytea) RETURNS text LANGUAGE sql AS $$
     SELECT translate(encode(data, 'base64'), E'+/=\n', '-_');
-$$;
+$$ IMMUTABLE;
 
 
 CREATE OR REPLACE FUNCTION url_decode(data text) RETURNS bytea LANGUAGE sql AS $$
@@ -15,7 +15,7 @@ WITH t AS (SELECT translate(data, '-_', '+/') AS trans),
            THEN repeat('=', (4 - rem.remainder))
            ELSE '' END,
     'base64') FROM t, rem;
-$$;
+$$ IMMUTABLE;
 
 
 CREATE OR REPLACE FUNCTION algorithm_sign(signables text, secret text, algorithm text)
@@ -28,7 +28,7 @@ WITH
       WHEN algorithm = 'HS512' THEN 'sha512'
       ELSE '' END AS id)  -- hmac throws error
 SELECT @extschema@.url_encode(@extschema@.hmac(signables, secret, alg.id)) FROM alg;
-$$;
+$$ IMMUTABLE;
 
 
 CREATE OR REPLACE FUNCTION sign(payload json, secret text, algorithm text DEFAULT 'HS256')
@@ -46,7 +46,7 @@ WITH
 SELECT
     signables.data || '.' ||
     @extschema@.algorithm_sign(signables.data, secret, algorithm) FROM signables;
-$$;
+$$ IMMUTABLE;
 
 
 CREATE OR REPLACE FUNCTION verify(token text, secret text, algorithm text DEFAULT 'HS256')
@@ -56,4 +56,4 @@ RETURNS table(header json, payload json, valid boolean) LANGUAGE sql AS $$
     convert_from(@extschema@.url_decode(r[2]), 'utf8')::json AS payload,
     r[3] = @extschema@.algorithm_sign(r[1] || '.' || r[2], secret, algorithm) AS valid
   FROM regexp_split_to_array(token, '\.') r;
-$$;
+$$ IMMUTABLE;
diff --git a/pgjwt--0.1.1.sql b/pgjwt--0.1.1.sql
new file mode 100644
index 0000000..d726438
--- /dev/null
+++ b/pgjwt--0.1.1.sql
@@ -0,0 +1,59 @@
+\echo Use "CREATE EXTENSION pgjwt" to load this file. \quit
+
+
+CREATE OR REPLACE FUNCTION url_encode(data bytea) RETURNS text LANGUAGE sql AS $$
+    SELECT translate(encode(data, 'base64'), E'+/=\n', '-_');
+$$ IMMUTABLE;
+
+
+CREATE OR REPLACE FUNCTION url_decode(data text) RETURNS bytea LANGUAGE sql AS $$
+WITH t AS (SELECT translate(data, '-_', '+/') AS trans),
+     rem AS (SELECT length(t.trans) % 4 AS remainder FROM t) -- compute padding size
+    SELECT decode(
+        t.trans ||
+        CASE WHEN rem.remainder > 0
+           THEN repeat('=', (4 - rem.remainder))
+           ELSE '' END,
+    'base64') FROM t, rem;
+$$ IMMUTABLE;
+
+
+CREATE OR REPLACE FUNCTION algorithm_sign(signables text, secret text, algorithm text)
+RETURNS text LANGUAGE sql AS $$
+WITH
+  alg AS (
+    SELECT CASE
+      WHEN algorithm = 'HS256' THEN 'sha256'
+      WHEN algorithm = 'HS384' THEN 'sha384'
+      WHEN algorithm = 'HS512' THEN 'sha512'
+      ELSE '' END AS id)  -- hmac throws error
+SELECT @extschema@.url_encode(@extschema@.hmac(signables, secret, alg.id)) FROM alg;
+$$ IMMUTABLE;
+
+
+CREATE OR REPLACE FUNCTION sign(payload json, secret text, algorithm text DEFAULT 'HS256')
+RETURNS text LANGUAGE sql AS $$
+WITH
+  header AS (
+    SELECT @extschema@.url_encode(convert_to('{"alg":"' || algorithm || '","typ":"JWT"}', 'utf8')) AS data
+    ),
+  payload AS (
+    SELECT @extschema@.url_encode(convert_to(payload::text, 'utf8')) AS data
+    ),
+  signables AS (
+    SELECT header.data || '.' || payload.data AS data FROM header, payload
+    )
+SELECT
+    signables.data || '.' ||
+    @extschema@.algorithm_sign(signables.data, secret, algorithm) FROM signables;
+$$ IMMUTABLE;
+
+
+CREATE OR REPLACE FUNCTION verify(token text, secret text, algorithm text DEFAULT 'HS256')
+RETURNS table(header json, payload json, valid boolean) LANGUAGE sql AS $$
+  SELECT
+    convert_from(@extschema@.url_decode(r[1]), 'utf8')::json AS header,
+    convert_from(@extschema@.url_decode(r[2]), 'utf8')::json AS payload,
+    r[3] = @extschema@.algorithm_sign(r[1] || '.' || r[2], secret, algorithm) AS valid
+  FROM regexp_split_to_array(token, '\.') r;
+$$ IMMUTABLE;
diff --git a/pgjwt.control b/pgjwt.control
index 85bd1b3..52ce820 100644
--- a/pgjwt.control
+++ b/pgjwt.control
@@ -1,5 +1,5 @@
 # pgjwt extension
 comment = 'JSON Web Token API for Postgresql'
-default_version = '0.1.0'
+default_version = '0.1.1'
 relocatable = false
 requires = pgcrypto