diff --git a/server/nm-store/src/sql/initialize_database.sql b/server/nm-store/src/sql/initialize_database.sql
index e72adba..3ad220d 100644
--- a/server/nm-store/src/sql/initialize_database.sql
+++ b/server/nm-store/src/sql/initialize_database.sql
@@ -32,7 +32,8 @@ CREATE TABLE note_relationships (
     kind TEXT NOT NULL,
 	-- If either note disappears, we want all the edges to disappear as well.
     FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE CASCADE,
-    FOREIGN KEY (parent_id) REFERENCES notes (id) ON DELETE CASCADE
+    FOREIGN KEY (parent_id) REFERENCES notes (id) ON DELETE CASCADE,
+	CHECK (note_id <> parent_id)
 );
 
 -- This table represents the graph of data relating notes to kastens.
@@ -43,6 +44,7 @@ CREATE TABLE note_kasten_relationships (
     kind TEXT NOT NULL,
 	-- If either note disappears, we want all the edges to disappear as well.
     FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE CASCADE,
-    FOREIGN KEY (kasten_id) REFERENCES notes (id) ON DELETE CASCADE
+    FOREIGN KEY (kasten_id) REFERENCES notes (id) ON DELETE CASCADE,
+	CHECK (note_id <> kasten_id)
 );