diff --git a/NEWS.md b/NEWS.md
index fe2bd71..b752422 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,7 @@
 0.35.0 (XXXX-XX-XX)
 * Reapply the changes in 0.33.0 (the issue we were looking for was unrelated)
 * Reapply `Make PG12 depend on plpython3u instead of plpythonu`
+* Fix identifier quotation in `CDB_UserDataSize`
 
 0.34.0 (2019-12-23)
 * Revert changes done in 0.33.0, keeping function signature to drop them
diff --git a/scripts-available/CDB_Quota.sql b/scripts-available/CDB_Quota.sql
index 96b41f2..9568b34 100644
--- a/scripts-available/CDB_Quota.sql
+++ b/scripts-available/CDB_Quota.sql
@@ -33,7 +33,7 @@ BEGIN
 
    IF raster_available THEN
        raster_read_query := Format('SELECT o_table_name, r_table_name FROM @postgisschema@.raster_overviews
-                        WHERE o_table_schema = ''%I'' AND o_table_catalog = current_database()', schema_name);
+                        WHERE o_table_schema = %L AND o_table_catalog = current_database()', schema_name);
    ELSE
        raster_read_query := 'SELECT NULL::text AS o_table_name, NULL::text AS r_table_name';
    END IF;
@@ -42,7 +42,7 @@ BEGIN
     %s
   ),
   user_tables AS (
-    SELECT table_name FROM @extschema@._CDB_NonAnalysisTablesInSchema(''%I'')
+    SELECT table_name FROM @extschema@._CDB_NonAnalysisTablesInSchema(%L)
   ),
   table_cat AS (
     SELECT
@@ -55,7 +55,7 @@ BEGIN
     FROM user_tables
   ),
   sizes AS (
-    SELECT COALESCE(INT8(SUM(@extschema@._CDB_total_relation_size(''%I'', table_name)))) table_size,
+    SELECT COALESCE(INT8(SUM(@extschema@._CDB_total_relation_size(%L, table_name)))) table_size,
       CASE
         WHEN is_overview THEN 0
 	WHEN is_raster THEN 1
diff --git a/test/CDB_QuotaTest.sql b/test/CDB_QuotaTest.sql
index bbb8753..670f4f6 100644
--- a/test/CDB_QuotaTest.sql
+++ b/test/CDB_QuotaTest.sql
@@ -60,6 +60,9 @@ SELECT 'excess3', catch_error($$INSERT INTO big VALUES (3);$$); -- disallowed, q
 DROP TABLE big;
 SELECT CDB_SetUserQuotaInBytes(0);
 
+CREATE SCHEMA "complex-name%_with'quotes""";
+SELECT CDB_UserDataSize('"complex-name%_with''quotes"');
+DROP SCHEMA "complex-name%_with'quotes""";
 
 set client_min_messages to NOTICE;
 DROP FUNCTION catch_error(text);
diff --git a/test/CDB_QuotaTest_expect b/test/CDB_QuotaTest_expect
index 49f9e7d..b982606 100644
--- a/test/CDB_QuotaTest_expect
+++ b/test/CDB_QuotaTest_expect
@@ -30,6 +30,9 @@ DROP TABLE
 excess3|t
 DROP TABLE
 0
+CREATE SCHEMA
+0
+DROP SCHEMA
 SET
 DROP FUNCTION
 DROP FUNCTION