diff --git a/atom b/atom
index 6481b3a..fc14e46 100755
--- a/atom
+++ b/atom
@@ -267,6 +267,7 @@ openDatabase() {
 		exec 5>&3
 		exec 3> >(tee -a $tempdir/debug.log >&5)
 	fi
+	echo 'PRAGMA foreign_keys = ON;' >&3
 }
 
 closeDatabase() {
diff --git a/share/schema.sql b/share/schema.sql
index d4f66e0..ac40b2a 100644
--- a/share/schema.sql
+++ b/share/schema.sql
@@ -8,6 +8,7 @@ CREATE TABLE source_files (
 	last_change	INTEGER NOT NULL DEFAULT (strftime('%s','now')),
 	last_seen	INTEGER	NOT NULL DEFAULT (strftime('%s','now')),
 	FOREIGN KEY	(mime_type)	REFERENCES mime_types(id)
+		ON DELETE SET NULL
 );
 CREATE TABLE destinations (
 	id		INTEGER PRIMARY KEY,
@@ -19,8 +20,10 @@ CREATE TABLE destination_files (
 	last_change	INTEGER	NOT NULL DEFAULT 0,
 	source_file_id	INTEGER,
 	destination_id	INTEGER,
-	FOREIGN KEY	(source_file_id)	REFERENCES source_files(id),
+	FOREIGN KEY	(source_file_id)	REFERENCES source_files(id)
+		ON DELETE SET NULL,
 	FOREIGN KEY	(destination_id)	REFERENCES destinations(id)
+		ON DELETE CASCADE
 );
 CREATE TABLE mime_types (
 	id		INTEGER PRIMARY KEY,
@@ -31,8 +34,9 @@ CREATE TABLE mime_actions (
 	mime_type	INTEGER,
 	destination_id	INTEGER,
 	action		INTEGER	DEFAULT 1,
-	FOREIGN KEY	(mime_type)	REFERENCES mime_types(id)
+	FOREIGN KEY	(mime_type)		REFERENCES mime_types(id),
 	FOREIGN KEY	(destination_id)	REFERENCES destinations(id)
+		ON DELETE CASCADE
 );
 
 CREATE VIEW mime_type_actions AS
@@ -66,9 +70,5 @@ BEGIN
 	INNER JOIN destinations
 		WHERE source_files.id=new.id;
 END;
-CREATE TRIGGER delete_destinations_files AFTER DELETE ON source_files
-BEGIN
-	UPDATE destination_files SET source_file_id=NULL WHERE source_file_id=old.id;
-END;
 
 COMMIT;