diff --git a/lib/taskana-core/src/main/resources/sql/taskana-schema.sql b/lib/taskana-core/src/main/resources/sql/taskana-schema.sql
index 56ea63c9f..39cee568d 100644
--- a/lib/taskana-core/src/main/resources/sql/taskana-schema.sql
+++ b/lib/taskana-core/src/main/resources/sql/taskana-schema.sql
@@ -12,7 +12,7 @@ CREATE TABLE CLASSIFICATION(
     CATEGORY VARCHAR(32),
     TYPE VARCHAR(32),
     DOMAIN VARCHAR(255) NOT NULL,
-    VALID_IN_DOMAIN BOOLEAN NOT NULL,
+    VALID_IN_DOMAIN SMALLINT NOT NULL,
     CREATED TIMESTAMP NULL,
     NAME VARCHAR(255) NULL,
     DESCRIPTION VARCHAR(255) NULL,
@@ -81,8 +81,8 @@ CREATE TABLE TASK (
         POR_INSTANCE VARCHAR(32) NOT NULL,
         POR_TYPE VARCHAR(32) NOT NULL,
         POR_VALUE VARCHAR(128) NOT NULL,
-        IS_READ BOOLEAN NOT NULL,
-        IS_TRANSFERRED BOOLEAN NOT NULL,
+        IS_READ SMALLINT NOT NULL,
+        IS_TRANSFERRED SMALLINT NOT NULL,
         CUSTOM_ATTRIBUTES CLOB NULL,
         CUSTOM_1 VARCHAR(255) NULL,
         CUSTOM_2 VARCHAR(255) NULL,
@@ -109,23 +109,23 @@ CREATE TABLE WORKBASKET_ACCESS_LIST(
         ID CHAR(40) NOT NULL,
         WORKBASKET_ID CHAR(40) NOT NULL,
         ACCESS_ID VARCHAR(255) NOT NULL,
-        PERM_READ BOOLEAN NOT NULL,
-        PERM_OPEN BOOLEAN NOT NULL,
-        PERM_APPEND BOOLEAN NOT NULL,
-        PERM_TRANSFER BOOLEAN NOT NULL,
-        PERM_DISTRIBUTE BOOLEAN NOT NULL,
-        PERM_CUSTOM_1 BOOLEAN NOT NULL,
-        PERM_CUSTOM_2 BOOLEAN NOT NULL,
-        PERM_CUSTOM_3 BOOLEAN NOT NULL,
-        PERM_CUSTOM_4 BOOLEAN NOT NULL,
-        PERM_CUSTOM_5 BOOLEAN NOT NULL,
-        PERM_CUSTOM_6 BOOLEAN NOT NULL,
-        PERM_CUSTOM_7 BOOLEAN NOT NULL,
-        PERM_CUSTOM_8 BOOLEAN NOT NULL,
-        PERM_CUSTOM_9 BOOLEAN NOT NULL,
-        PERM_CUSTOM_10 BOOLEAN NOT NULL,
-        PERM_CUSTOM_11 BOOLEAN NOT NULL,
-        PERM_CUSTOM_12 BOOLEAN NOT NULL,
+        PERM_READ SMALLINT NOT NULL,
+        PERM_OPEN SMALLINT NOT NULL,
+        PERM_APPEND SMALLINT NOT NULL,
+        PERM_TRANSFER SMALLINT NOT NULL,
+        PERM_DISTRIBUTE SMALLINT NOT NULL,
+        PERM_CUSTOM_1 SMALLINT NOT NULL,
+        PERM_CUSTOM_2 SMALLINT NOT NULL,
+        PERM_CUSTOM_3 SMALLINT NOT NULL,
+        PERM_CUSTOM_4 SMALLINT NOT NULL,
+        PERM_CUSTOM_5 SMALLINT NOT NULL,
+        PERM_CUSTOM_6 SMALLINT NOT NULL,
+        PERM_CUSTOM_7 SMALLINT NOT NULL,
+        PERM_CUSTOM_8 SMALLINT NOT NULL,
+        PERM_CUSTOM_9 SMALLINT NOT NULL,
+        PERM_CUSTOM_10 SMALLINT NOT NULL,
+        PERM_CUSTOM_11 SMALLINT NOT NULL,
+        PERM_CUSTOM_12 SMALLINT NOT NULL,
         PRIMARY KEY (ID)
 );