diff --git a/packages/database/src/api/Database.ts b/packages/database/src/api/Database.ts
index 72ae85c08a1..29ea7a433b1 100644
--- a/packages/database/src/api/Database.ts
+++ b/packages/database/src/api/Database.ts
@@ -27,6 +27,7 @@ import { Provider } from '@firebase/component';
 import {
   getModularInstance,
   createMockUserToken,
+  // deepEqual,
   EmulatorMockTokenOptions,
   getDefaultEmulatorHostnameAndPort
 } from '@firebase/util';
@@ -38,7 +39,7 @@ import {
   FirebaseAuthTokenProvider
 } from '../core/AuthTokenProvider';
 import { Repo, repoInterrupt, repoResume, repoStart } from '../core/Repo';
-import { RepoInfo } from '../core/RepoInfo';
+import { RepoInfo, RepoInfoEmulatorOptions} from '../core/RepoInfo';
 import { parseRepoInfo } from '../core/util/libs/parser';
 import { newEmptyPath, pathIsEmpty } from '../core/util/Path';
 import {
@@ -84,19 +85,20 @@ let useRestClient = false;
  */
 function repoManagerApplyEmulatorSettings(
   repo: Repo,
-  host: string,
-  port: number,
-  tokenProvider?: AuthTokenProvider
+  hostAndPort: string,
+  emulatorOptions: RepoInfoEmulatorOptions,
+  tokenProvider?: AuthTokenProvider,
 ): void {
   repo.repoInfo_ = new RepoInfo(
-    `${host}:${port}`,
+    hostAndPort,
     /* secure= */ false,
     repo.repoInfo_.namespace,
     repo.repoInfo_.webSocketOnly,
     repo.repoInfo_.nodeAdmin,
     repo.repoInfo_.persistenceKey,
     repo.repoInfo_.includeNamespaceInQueryParams,
-    /*isUsingEmulator=*/ true
+    /*isUsingEmulator=*/ true,
+    emulatorOptions
   );
 
   if (tokenProvider) {
@@ -350,13 +352,23 @@ export function connectDatabaseEmulator(
 ): void {
   db = getModularInstance(db);
   db._checkNotDeleted('useEmulator');
+  const hostAndPort = `${host}:${port}`;
+  const repo = db._repoInternal;
   if (db._instanceStarted) {
+    // If the instance has already been started, then silenty fail if this function is called again
+    // with the same parameters. If the parameters differ then assert.
+    if (
+      true
+      // hostAndPort === db._repoInternal.repoInfo_.host //&&
+      //deepEqual(options, repo.repoInfo_.emulatorOptions)
+    ) {
+      return;
+    }
     fatal(
-      'Cannot call useEmulator() after instance has already been initialized.'
+      'connectDatabaseEmulator() cannot alter the emulator configuration after the database instance has started.'
     );
   }
 
-  const repo = db._repoInternal;
   let tokenProvider: EmulatorTokenProvider | undefined = undefined;
   if (repo.repoInfo_.nodeAdmin) {
     if (options.mockUserToken) {
@@ -374,7 +386,7 @@ export function connectDatabaseEmulator(
   }
 
   // Modify the repo to apply emulator settings
-  repoManagerApplyEmulatorSettings(repo, host, port, tokenProvider);
+  repoManagerApplyEmulatorSettings(repo, hostAndPort, options, tokenProvider);
 }
 
 /**
diff --git a/packages/database/src/core/RepoInfo.ts b/packages/database/src/core/RepoInfo.ts
index 025b746b951..2f2fd61ae30 100644
--- a/packages/database/src/core/RepoInfo.ts
+++ b/packages/database/src/core/RepoInfo.ts
@@ -22,15 +22,16 @@ import { LONG_POLLING, WEBSOCKET } from '../realtime/Constants';
 import { PersistentStorage } from './storage/storage';
 import { each } from './util/util';
 
+export interface RepoInfoEmulatorOptions {
+  mockUserToken?: string | EmulatorMockTokenOptions;
+};
+
 /**
  * A class that holds metadata about a Repo object
  */
 export class RepoInfo {
   private _host: string;
   private _domain: string;
-  private _emulatorOptions: {
-    mockUserToken?: EmulatorMockTokenOptions | string;
-  };
   internalHost: string;
 
   /**
@@ -49,11 +50,11 @@ export class RepoInfo {
     public readonly nodeAdmin: boolean = false,
     public readonly persistenceKey: string = '',
     public readonly includeNamespaceInQueryParams: boolean = false,
-    public readonly isUsingEmulator: boolean = false
+    public readonly isUsingEmulator: boolean = false,
+    public readonly emulatorOptions: RepoInfoEmulatorOptions | null = null
   ) {
     this._host = host.toLowerCase();
     this._domain = this._host.substr(this._host.indexOf('.') + 1);
-    this._emulatorOptions = {};
     this.internalHost =
       (PersistentStorage.get('host:' + host) as string) || this._host;
   }
@@ -82,12 +83,6 @@ export class RepoInfo {
     }
   }
 
-  get emulatorOptions(): {
-    mockUserToken?: EmulatorMockTokenOptions | string;
-  } {
-    return this._emulatorOptions;
-  }
-
   toString(): string {
     let str = this.toURLString();
     if (this.persistenceKey) {