diff --git a/src/sqlite/external_servers_preferences.sql b/src/sqlite/external_servers_preferences.sql
index 83944f5..00b72e4 100644
--- a/src/sqlite/external_servers_preferences.sql
+++ b/src/sqlite/external_servers_preferences.sql
@@ -1,7 +1,7 @@
 -- external_servers_preferences definition
 
 CREATE TABLE external_servers_preferences (
-	id INTEGER NOT NULL PRIMARY KEY,
+	id BLOB NOT NULL PRIMARY KEY,
 	external_servers BLOB NOT NULL,
 	external_servers_limit TEXT NOT NULL,
 	CONSTRAINT external_servers_preferences_FK FOREIGN KEY (id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE
diff --git a/src/sqlite/external_servers_privacy_preferences.sql b/src/sqlite/external_servers_privacy_preferences.sql
index 9ea5a44..43c530c 100644
--- a/src/sqlite/external_servers_privacy_preferences.sql
+++ b/src/sqlite/external_servers_privacy_preferences.sql
@@ -1,7 +1,7 @@
 -- external_servers_privacy_preferences definition
 
 CREATE TABLE external_servers_privacy_preferences (
-	id INTEGER NOT NULL PRIMARY KEY,
+	id BLOB NOT NULL PRIMARY KEY,
 	discovery BLOB NOT NULL,
 	discovery_user_limit TEXT NOT NULL,
 	discovery_server_limit TEXT NOT NULL,
diff --git a/src/sqlite/notification_preferences.sql b/src/sqlite/notification_preferences.sql
index 36ab5d7..498b232 100644
--- a/src/sqlite/notification_preferences.sql
+++ b/src/sqlite/notification_preferences.sql
@@ -1,8 +1,8 @@
 -- notification_preferences definition
 
 CREATE TABLE notification_preferences (
-	id INTEGER NOT NULL PRIMARY KEY,
-	lock_details INTEGER DEFAULT 0 NOT NULL,
-	do_not_disturb INTEGER DEFAULT 0 NOT NULL,
+	id BLOB NOT NULL PRIMARY KEY,
+	lock_details BOOLEAN DEFAULT 0 NOT NULL CHECK (lock_details IN (0, 1)),
+	do_not_disturb INTEGER DEFAULT 0 NOT NULL CHECK (do_not_disturb IN (0, 1)),
 	CONSTRAINT notification_preferences_FK FOREIGN KEY (id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE
 );
\ No newline at end of file
diff --git a/src/sqlite/privacy_preferences.sql b/src/sqlite/privacy_preferences.sql
index 28cfd21..445bf03 100644
--- a/src/sqlite/privacy_preferences.sql
+++ b/src/sqlite/privacy_preferences.sql
@@ -1,14 +1,14 @@
 -- privacy_preferences definition
 
 CREATE TABLE privacy_preferences (
-	id INTEGER NOT NULL PRIMARY KEY,
+	id BLOB NOT NULL PRIMARY KEY,
 	discovery BLOB NOT NULL,
 	discovery_user_limit TEXT NOT NULL,
 	discovery_server_limit TEXT NOT NULL,
 	last_seen BLOB NOT NULL,
 	last_seen_user_limit TEXT NOT NULL,
 	last_seen_server_limit TEXT NOT NULL,
-	last_seen_course INTEGER DEFAULT 0 NOT NULL,
+	last_seen_course BOOLEAN DEFAULT 0 NOT NULL CHECK (last_seen_course IN (0, 1)),
 	info BLOB NOT NULL,
 	info_user_limit TEXT NOT NULL,
 	info_server_limit TEXT NOT NULL,
diff --git a/src/sqlite/security_preferences.sql b/src/sqlite/security_preferences.sql
index 9ce04a5..50ce979 100644
--- a/src/sqlite/security_preferences.sql
+++ b/src/sqlite/security_preferences.sql
@@ -1,7 +1,7 @@
 -- security_preferences definition
 
 CREATE TABLE "security_preferences" (
-	id INTEGER NOT NULL PRIMARY KEY,
+	id BLOB NOT NULL PRIMARY KEY,
 	account_tokens TEXT NOT NULL,
 	password_hash TEXT NOT NULL,
 	CONSTRAINT NewTable_FK FOREIGN KEY (id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE
diff --git a/src/sqlite/users.sql b/src/sqlite/users.sql
index 4dfc8c6..66500e7 100644
--- a/src/sqlite/users.sql
+++ b/src/sqlite/users.sql
@@ -1,10 +1,10 @@
 -- users definition
 
 CREATE TABLE users (
-	id INTEGER NOT NULL PRIMARY KEY,
+	id BLOB NOT NULL PRIMARY KEY,
 	user_name TEXT NOT NULL,
 	display_name TEXT,
-	activated INTEGER DEFAULT 0 NOT NULL,
+	activated BOOLEAN DEFAULT 0 NOT NULL CHECK (activated IN (0, 1)),
 	created INTEGER NOT NULL,
 	last_online INTEGER
 );
\ No newline at end of file