diff --git a/cli/src/commands/worktree.ts b/cli/src/commands/worktree.ts
index 7311793..e807daf 100644
--- a/cli/src/commands/worktree.ts
+++ b/cli/src/commands/worktree.ts
@@ -83,6 +83,7 @@ type EmbeddedPostgresCtor = new (opts: {
   password: string;
   port: number;
   persistent: boolean;
+  initdbFlags?: string[];
   onLog?: (message: unknown) => void;
   onError?: (message: unknown) => void;
 }) => EmbeddedPostgresInstance;
diff --git a/packages/db/src/migration-runtime.ts b/packages/db/src/migration-runtime.ts
index 10b7b9b..e07bdf0 100644
--- a/packages/db/src/migration-runtime.ts
+++ b/packages/db/src/migration-runtime.ts
@@ -17,6 +17,7 @@ type EmbeddedPostgresCtor = new (opts: {
   password: string;
   port: number;
   persistent: boolean;
+  initdbFlags?: string[];
   onLog?: (message: unknown) => void;
   onError?: (message: unknown) => void;
 }) => EmbeddedPostgresInstance;
diff --git a/server/src/index.ts b/server/src/index.ts
index 50c6a7b..0479f87 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -53,6 +53,7 @@ type EmbeddedPostgresCtor = new (opts: {
   password: string;
   port: number;
   persistent: boolean;
+  initdbFlags?: string[];
   onLog?: (message: unknown) => void;
   onError?: (message: unknown) => void;
 }) => EmbeddedPostgresInstance;