diff --git a/firebase-firestore/api/android/firebase-firestore.api b/firebase-firestore/api/android/firebase-firestore.api
index 8a0aa2e9a..3e0bf4cd7 100644
--- a/firebase-firestore/api/android/firebase-firestore.api
+++ b/firebase-firestore/api/android/firebase-firestore.api
@@ -730,7 +730,8 @@ public final class dev/gitlive/firebase/firestore/_encodersKt {
 }
 
 public final class dev/gitlive/firebase/firestore/android {
-	public static final fun firestore (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
+	public static final fun firestore (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;Ljava/lang/String;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
+	public static synthetic fun firestore$default (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;Ljava/lang/String;ILjava/lang/Object;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
 	public static final fun firestoreSettings (Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;Lkotlin/jvm/functions/Function1;)Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;
 	public static synthetic fun firestoreSettings$default (Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;
 	public static final fun getAndroid (Ldev/gitlive/firebase/firestore/CollectionReference;)Lcom/google/firebase/firestore/CollectionReference;
diff --git a/firebase-firestore/api/jvm/firebase-firestore.api b/firebase-firestore/api/jvm/firebase-firestore.api
index 33a64aef7..bab3a265e 100644
--- a/firebase-firestore/api/jvm/firebase-firestore.api
+++ b/firebase-firestore/api/jvm/firebase-firestore.api
@@ -730,7 +730,8 @@ public final class dev/gitlive/firebase/firestore/_encodersKt {
 }
 
 public final class dev/gitlive/firebase/firestore/android {
-	public static final fun firestore (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
+	public static final fun firestore (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;Ljava/lang/String;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
+	public static synthetic fun firestore$default (Ldev/gitlive/firebase/Firebase;Ldev/gitlive/firebase/FirebaseApp;Ljava/lang/String;ILjava/lang/Object;)Ldev/gitlive/firebase/firestore/FirebaseFirestore;
 	public static final fun firestoreSettings (Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;Lkotlin/jvm/functions/Function1;)Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;
 	public static synthetic fun firestoreSettings$default (Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Ldev/gitlive/firebase/firestore/FirebaseFirestoreSettings;
 	public static final fun getAndroid (Ldev/gitlive/firebase/firestore/CollectionReference;)Lcom/google/firebase/firestore/CollectionReference;
diff --git a/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt b/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
index 01106caae..30fbc7ed6 100644
--- a/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
+++ b/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
@@ -36,8 +36,8 @@ public val FirebaseFirestore.android: AndroidFirebaseFirestore get() = AndroidFi
 public actual val Firebase.firestore: FirebaseFirestore get() =
     FirebaseFirestore(AndroidFirebaseFirestore.getInstance())
 
-public actual fun Firebase.firestore(app: FirebaseApp): FirebaseFirestore =
-    FirebaseFirestore(AndroidFirebaseFirestore.getInstance(app.android))
+public actual fun Firebase.firestore(app: FirebaseApp, databaseId: String?): FirebaseFirestore =
+    FirebaseFirestore(databaseId?.let { AndroidFirebaseFirestore.getInstance(app.android, databaseId) } ?: AndroidFirebaseFirestore.getInstance(app.android))
 
 public val LocalCacheSettings.android: AndroidLocalCacheSettings get() = when (this) {
     is LocalCacheSettings.Persistent -> androidPersistentCacheSettings {
diff --git a/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt b/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
index c3f08216a..78e0ffd50 100644
--- a/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
+++ b/firebase-firestore/src/androidMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
@@ -8,7 +8,7 @@ import dev.gitlive.firebase.firestore.android
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.tasks.await
 
-internal actual class NativeFirebaseFirestoreWrapper actual constructor(actual val native: NativeFirebaseFirestore) {
+internal actual class NativeFirebaseFirestoreWrapper actual constructor(actual val native: NativeFirebaseFirestore, actual val databaseId: String?) {
 
     actual fun collection(collectionPath: String) = native.collection(collectionPath)
 
diff --git a/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt b/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
index bf4723e49..736e413f3 100644
--- a/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
+++ b/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
@@ -32,7 +32,7 @@ import kotlin.jvm.JvmName
 public expect val Firebase.firestore: FirebaseFirestore
 
 /** Returns the [FirebaseFirestore] instance of a given [FirebaseApp]. */
-public expect fun Firebase.firestore(app: FirebaseApp): FirebaseFirestore
+public expect fun Firebase.firestore(app: FirebaseApp, databaseId: String? = null): FirebaseFirestore
 
 internal expect class NativeFirebaseFirestore
 
diff --git a/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt b/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
index b617deb45..fcc236c61 100644
--- a/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
+++ b/firebase-firestore/src/commonMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
@@ -7,8 +7,9 @@ import dev.gitlive.firebase.firestore.NativeQuery
 import dev.gitlive.firebase.firestore.NativeTransaction
 import dev.gitlive.firebase.firestore.NativeWriteBatch
 
-internal expect class NativeFirebaseFirestoreWrapper internal constructor(native: NativeFirebaseFirestore) {
+internal expect class NativeFirebaseFirestoreWrapper internal constructor(native: NativeFirebaseFirestore, databaseId: String? = null) {
     val native: NativeFirebaseFirestore
+    val databaseId: String?
 
     fun collection(collectionPath: String): NativeCollectionReference
     fun collectionGroup(collectionId: String): NativeQuery
diff --git a/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt b/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
index 605281ec0..1740ec26e 100644
--- a/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
+++ b/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
@@ -25,8 +25,8 @@ public val FirebaseFirestore.ios: FIRFirestore get() = FIRFirestore.firestore()
 public actual val Firebase.firestore: FirebaseFirestore get() =
     FirebaseFirestore(FIRFirestore.firestore())
 
-public actual fun Firebase.firestore(app: FirebaseApp): FirebaseFirestore = FirebaseFirestore(
-    FIRFirestore.firestoreForApp(app.ios as objcnames.classes.FIRApp),
+public actual fun Firebase.firestore(app: FirebaseApp, databaseId: String?): FirebaseFirestore = FirebaseFirestore(
+    databaseId?.let { FIRFirestore.firestoreForApp(app.ios as objcnames.classes.FIRApp, it) } ?: FIRFirestore.firestoreForApp(app.ios as objcnames.classes.FIRApp),
 )
 
 public val LocalCacheSettings.ios: FIRLocalCacheSettingsProtocol get() = when (this) {
diff --git a/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt b/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
index 50e59c0ad..e3d9d269e 100644
--- a/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
+++ b/firebase-firestore/src/iosMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
@@ -9,7 +9,7 @@ import dev.gitlive.firebase.firestore.awaitResult
 import kotlinx.coroutines.runBlocking
 
 @Suppress("UNCHECKED_CAST")
-internal actual class NativeFirebaseFirestoreWrapper internal actual constructor(actual val native: NativeFirebaseFirestore) {
+internal actual class NativeFirebaseFirestoreWrapper internal actual constructor(actual val native: NativeFirebaseFirestore, actual val databaseId: String?) {
 
     actual fun collection(collectionPath: String) = native.collectionWithPath(collectionPath)
 
diff --git a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/externals/firestore.kt b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/externals/firestore.kt
index 31c110099..00d8de655 100644
--- a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/externals/firestore.kt
+++ b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/externals/firestore.kt
@@ -81,7 +81,7 @@ public external fun getDocsFromCache(query: Query): Promise<QuerySnapshot>
 
 public external fun getDocsFromServer(query: Query): Promise<QuerySnapshot>
 
-public external fun getFirestore(app: FirebaseApp? = definedExternally): Firestore
+public external fun getFirestore(app: FirebaseApp? = definedExternally, databaseId: String? = definedExternally): Firestore
 
 public external fun increment(n: Int): FieldValue
 
diff --git a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
index 752e53a3c..17c1b3b43 100644
--- a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
+++ b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/firestore.kt
@@ -33,10 +33,10 @@ import dev.gitlive.firebase.firestore.externals.WriteBatch as JsWriteBatch
 import dev.gitlive.firebase.firestore.externals.documentId as jsDocumentId
 
 public actual val Firebase.firestore: FirebaseFirestore get() =
-    rethrow { FirebaseFirestore(NativeFirebaseFirestoreWrapper(getApp())) }
+    rethrow { FirebaseFirestore(NativeFirebaseFirestoreWrapper(getApp(), null)) }
 
-public actual fun Firebase.firestore(app: FirebaseApp): FirebaseFirestore =
-    rethrow { FirebaseFirestore(NativeFirebaseFirestoreWrapper(app.js)) }
+public actual fun Firebase.firestore(app: FirebaseApp, databaseId: String?): FirebaseFirestore =
+    rethrow { FirebaseFirestore(NativeFirebaseFirestoreWrapper(app.js, databaseId)) }
 
 internal actual data class NativeFirebaseFirestore(val js: JsFirestore)
 
diff --git a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
index c8c1a31ae..224725946 100644
--- a/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
+++ b/firebase-firestore/src/jsMain/kotlin/dev/gitlive/firebase/firestore/internal/NativeFirebaseFirestoreWrapper.kt
@@ -23,27 +23,30 @@ import kotlinx.coroutines.promise
 
 internal actual class NativeFirebaseFirestoreWrapper internal constructor(
     private val createNative: NativeFirebaseFirestoreWrapper.(FirebaseFirestoreSettings?) -> NativeFirebaseFirestore,
+    actual val databaseId: String?,
 ) {
 
-    internal actual constructor(native: NativeFirebaseFirestore) : this(
+    internal actual constructor(native: NativeFirebaseFirestore, databaseId: String?) : this(
         { settings ->
             settings?.let {
-                NativeFirebaseFirestore(initializeFirestore(native.js.app, settings))
+                NativeFirebaseFirestore(initializeFirestore(native.js.app, settings, databaseId))
             } ?: native
         },
+        databaseId,
     )
-    internal constructor(app: FirebaseApp) : this(
+    internal constructor(app: FirebaseApp, databaseId: String?) : this(
         { settings ->
             NativeFirebaseFirestore(
                 settings?.let {
-                    initializeFirestore(app, it.js).also {
+                    initializeFirestore(app, it.js, databaseId).also {
                         emulatorSettings?.run {
                             connectFirestoreEmulator(it, host, port)
                         }
                     }
-                } ?: getFirestore(app),
+                } ?: getFirestore(app, databaseId),
             )
         },
+        databaseId,
     )
 
     private data class EmulatorSettings(val host: String, val port: Int)