diff --git a/cmd/server/tests/schema_idempotency_test.go b/cmd/server/tests/schema_idempotency_test.go
new file mode 100644
index 0000000..aadcfc3
--- /dev/null
+++ b/cmd/server/tests/schema_idempotency_test.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"context"
+	"testing"
+
+	"bookhoard/internal/config"
+	"bookhoard/internal/database"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/stretchr/testify/require"
+)
+
+// TestSchemaInitializationIsIdempotent replays the application's production
+// schema initializer twice against the same database. schema.sql runs on
+// EVERY app startup, so it must apply cleanly to a database where a previous
+// startup already applied it. A regression here crash-loops the production
+// container on its second boot (e.g. SQLSTATE 2BP01: DROP FUNCTION refused
+// while a trigger created by the previous run still references it).
+//
+// Uses a dedicated pool: production Initialize holds the advisory lock on one
+// connection while executing the schema on another, but the shared test pool
+// is capped at MaxConns=1 and would deadlock.
+func TestSchemaInitializationIsIdempotent(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping schema re-initialization in -short mode")
+	}
+
+	// Bring up the standard test environment (seeds users, starts server).
+	setup := setupTestServer(t)
+	defer func() { _ = setup.Close() }()
+
+	// Dedicated pool with default connection limits for the initializer.
+	poolCfg, err := pgxpool.ParseConfig(config.LoadConfig().DatabaseURL())
+	require.NoError(t, err, "failed to parse database URL")
+	pool, err := pgxpool.NewWithConfig(context.Background(), poolCfg)
+	require.NoError(t, err, "failed to connect for schema initialization test")
+	defer func() { pool.Close() }()
+
+	ctx := context.Background()
+
+	// First boot: applies the schema to the (possibly fresh) database.
+	if err := database.Initialize(ctx, pool); err != nil {
+		t.Fatalf("first schema initialization failed: %v", err)
+	}
+
+	// Second boot against the now-initialized database: this is exactly
+	// where non-idempotent statements (bare CREATE TRIGGER, DROP FUNCTION
+	// with dependent objects, etc.) blow up.
+	if err := database.Initialize(ctx, pool); err != nil {
+		t.Fatalf("second schema initialization failed: %v — schema.sql must stay idempotent across restarts", err)
+	}
+}
diff --git a/database/schema/schema.sql b/database/schema/schema.sql
index bdfccd0..57c180c 100644
--- a/database/schema/schema.sql
+++ b/database/schema/schema.sql
@@ -259,8 +259,11 @@ CREATE INDEX IF NOT EXISTS idx_media_items_archived ON media_items (archived_at)
 CREATE INDEX IF NOT EXISTS idx_media_items_tags_search ON media_items USING GIN (tags_search);
 CREATE INDEX IF NOT EXISTS idx_media_items_contributors_search ON media_items USING GIN (contributors_search);
 
--- Drop existing trigger if exists
+-- Drop existing triggers if exists. Both must be dropped BEFORE the function:
+-- dropping a function that triggers still reference fails (SQLSTATE 2BP01),
+-- which would abort the schema transaction on every startup after the first.
 DROP TRIGGER IF EXISTS set_library_type_name_on_insert ON media_items;
+DROP TRIGGER IF EXISTS set_library_type_name_on_library_change ON media_items;
 -- Drop existing function if exists
 DROP FUNCTION IF EXISTS set_library_type_name();
 
@@ -279,6 +282,14 @@ CREATE TRIGGER set_library_type_name_on_insert
   FOR EACH ROW
   EXECUTE FUNCTION set_library_type_name();
 
+-- Keep library_type_name truthful when an item is repointed to another
+-- library (cross-library move detection reuses the same function; the row
+-- keeps its ID while its library changes).
+CREATE TRIGGER set_library_type_name_on_library_change
+  BEFORE UPDATE OF library_id ON media_items
+  FOR EACH ROW
+  EXECUTE FUNCTION set_library_type_name();
+
 -- Add GIN indexes for pg_trgm fuzzy search performance
 CREATE INDEX IF NOT EXISTS idx_media_items_author_trgm
   ON media_items USING GIN (author gin_trgm_ops);