diff --git a/database/core.tsql b/database/core.tsql
index 27352e5fb343fb29c1ea93dc2be4cb892a19d5dc..d88bb64ab3b4ae845fdc23bd54f9ae6d8a225aa8 100644
--- a/database/core.tsql
+++ b/database/core.tsql
@@ -19,12 +19,15 @@ CREATE INDEX @PREFIX@users_idx1 ON @PREFIX@users (Username);
 CREATE TABLE @PREFIX@user_attributes (
 	ID			@SERIAL_TYPE@,
 
+	UserID			@SERIAL_REF_TYPE@ NOT NULL,
+
 	Name			VARCHAR(255) NOT NULL,
 	Operator		VARCHAR(3) NOT NULL,
 	Value			VARCHAR(255),
 
 	Disabled		SMALLINT NOT NULL DEFAULT '0',
 
+	FOREIGN KEY (UserID) REFERENCES @PREFIX@users(ID),
 	UNIQUE (Name)
 ) @CREATE_TABLE_SUFFIX@;
 
@@ -50,12 +53,15 @@ CREATE INDEX @PREFIX@groups_idx1 ON @PREFIX@groups (Name);
 CREATE TABLE @PREFIX@group_attributes (
 	ID			@SERIAL_TYPE@,
 
+	GroupID			@SERIAL_REF_TYPE@ NOT NULL,
+
 	Name			VARCHAR(255) NOT NULL,
 	Operator		VARCHAR(3) NOT NULL,
 	Value			VARCHAR(255),
 
 	Disabled		SMALLINT NOT NULL DEFAULT '0',
 
+	FOREIGN KEY (GroupID) REFERENCES @PREFIX@groups(ID),
 	UNIQUE (Name)
 ) @CREATE_TABLE_SUFFIX@;