diff --git a/FirebaseAuth/CHANGELOG.md b/FirebaseAuth/CHANGELOG.md
index 01349d8f334..62a5762a5cd 100644
--- a/FirebaseAuth/CHANGELOG.md
+++ b/FirebaseAuth/CHANGELOG.md
@@ -1,3 +1,6 @@
+# Unreleased
+- [fixed] Replaced unsafe uses of `os_unfair_lock` (#14548).
+
 # 11.9.0
 - [changed] Using reCAPTCHA Enterprise and Firebase Auth requires reCAPTCHA
   Enterprise 18.7.0 or later.
diff --git a/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift b/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
index 649d274c294..355373104d4 100644
--- a/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
+++ b/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
@@ -33,7 +33,7 @@ class AuthComponent: NSObject, Library, ComponentLifecycleMaintainer {
   private var instances: [String: Auth] = [:]
 
   /// Lock to manage access to the instances array to avoid race conditions.
-  private var instancesLock: os_unfair_lock = .init()
+  private let instancesLock = OSAllocatedUnfairLock()
 
   // MARK: - Initializers
 
@@ -58,10 +58,10 @@ class AuthComponent: NSObject, Library, ComponentLifecycleMaintainer {
   // MARK: - AuthProvider conformance
 
   @discardableResult func auth() -> Auth {
-    os_unfair_lock_lock(&instancesLock)
+    instancesLock.lock()
 
     // Unlock before the function returns.
-    defer { os_unfair_lock_unlock(&instancesLock) }
+    defer { instancesLock.unlock() }
 
     if let instance = instances[app.name] {
       return instance
diff --git a/FirebaseFunctions/CHANGELOG.md b/FirebaseFunctions/CHANGELOG.md
index 89a663ec718..58cf04f7a58 100644
--- a/FirebaseFunctions/CHANGELOG.md
+++ b/FirebaseFunctions/CHANGELOG.md
@@ -1,3 +1,6 @@
+# Unreleased
+- [fixed] Replaced unsafe uses of `os_unfair_lock` (#14548).
+
 # 11.9.0
 - [fixed] Fixed App Check token reporting to enable differentiating outdated
   (`MISSING`) and inauthentic (`INVALID`) clients; see [Monitor App Check
diff --git a/FirebaseFunctions/Sources/Functions.swift b/FirebaseFunctions/Sources/Functions.swift
index ce189579c87..59ad8ce52d2 100644
--- a/FirebaseFunctions/Sources/Functions.swift
+++ b/FirebaseFunctions/Sources/Functions.swift
@@ -56,7 +56,7 @@ enum FunctionsConstants {
   private static var instances: [String: [Functions]] = [:]
 
   /// Lock to manage access to the instances array to avoid race conditions.
-  private static var instancesLock: os_unfair_lock = .init()
+  private static let instancesLock = OSAllocatedUnfairLock()
 
   /// The custom domain to use for all functions references (optional).
   let customDomain: String?
@@ -304,10 +304,10 @@ enum FunctionsConstants {
     guard let app else {
       fatalError("`FirebaseApp.configure()` needs to be called before using Functions.")
     }
-    os_unfair_lock_lock(&instancesLock)
+    instancesLock.lock()
 
     // Unlock before the function returns.
-    defer { os_unfair_lock_unlock(&instancesLock) }
+    defer { instancesLock.unlock() }
 
     if let associatedInstances = instances[app.name] {
       for instance in associatedInstances {
diff --git a/FirebaseStorage/CHANGELOG.md b/FirebaseStorage/CHANGELOG.md
index cb40acb0b9f..af4496d0ed7 100644
--- a/FirebaseStorage/CHANGELOG.md
+++ b/FirebaseStorage/CHANGELOG.md
@@ -1,3 +1,6 @@
+# Unreleased
+- [fixed] Replaced unsafe uses of `os_unfair_lock` (#14548).
+
 # 11.1.0
 - [fixed] Fix a potential data race in Storage initialization. (#13369)
 
diff --git a/FirebaseStorage/Sources/Storage.swift b/FirebaseStorage/Sources/Storage.swift
index b58cc4a8c30..ad03eaf77c3 100644
--- a/FirebaseStorage/Sources/Storage.swift
+++ b/FirebaseStorage/Sources/Storage.swift
@@ -249,13 +249,13 @@ import FirebaseCore
     private var instances: [String: Storage] = [:]
 
     /// Lock to manage access to the instances array to avoid race conditions.
-    private var instancesLock: os_unfair_lock = .init()
+private let instancesLock = OSAllocatedUnfairLock()
 
     private init() {}
 
     func storage(app: FirebaseApp, bucket: String) -> Storage {
-      os_unfair_lock_lock(&instancesLock)
-      defer { os_unfair_lock_unlock(&instancesLock) }
+      instancesLock.lock()
+      defer { instancesLock.unlock() }
 
       if let instance = instances[bucket] {
         return instance
diff --git a/FirebaseVertexAI/CHANGELOG.md b/FirebaseVertexAI/CHANGELOG.md
index e7fc4c18d6c..28bc66c263b 100644
--- a/FirebaseVertexAI/CHANGELOG.md
+++ b/FirebaseVertexAI/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Unreleased
 - [feature] The Vertex AI SDK no longer requires `@preconcurrency` when imported in Swift 6.
 - [feature] The Vertex AI Sample App now includes an image generation example.
+- [fixed] Replaced unsafe uses of `os_unfair_lock` (#14548).
 
 # 11.9.0
 - [feature] **Public Preview**: Added support for generating images using the
diff --git a/FirebaseVertexAI/Sources/VertexAI.swift b/FirebaseVertexAI/Sources/VertexAI.swift
index 16fc8be0561..2d62ec43dd8 100644
--- a/FirebaseVertexAI/Sources/VertexAI.swift
+++ b/FirebaseVertexAI/Sources/VertexAI.swift
@@ -124,20 +124,17 @@ public class VertexAI {
 
   let apiConfig: APIConfig
 
+  /// Lock to manage access to the `instances` array to avoid race conditions.
+  private static let instancesLock = OSAllocatedUnfairLock()
+
   #if compiler(>=6)
     /// A map of active  `VertexAI` instances keyed by the `FirebaseApp` name and the `location`, in
     /// the format `appName:location`.
     private nonisolated(unsafe) static var instances: [InstanceKey: VertexAI] = [:]
-
-    /// Lock to manage access to the `instances` array to avoid race conditions.
-    private nonisolated(unsafe) static var instancesLock: os_unfair_lock = .init()
   #else
     /// A map of active  `VertexAI` instances keyed by the `FirebaseApp` name and the `location`, in
     /// the format `appName:location`.
     private static var instances: [InstanceKey: VertexAI] = [:]
-
-    /// Lock to manage access to the `instances` array to avoid race conditions.
-    private static var instancesLock: os_unfair_lock = .init()
   #endif
 
   let location: String?
@@ -149,10 +146,10 @@ public class VertexAI {
       fatalError("No instance of the default Firebase app was found.")
     }
 
-    os_unfair_lock_lock(&instancesLock)
+    instancesLock.lock()
 
     // Unlock before the function returns.
-    defer { os_unfair_lock_unlock(&instancesLock) }
+    defer { instancesLock.unlock() }
 
     let instanceKey = InstanceKey(appName: app.name, location: location, apiConfig: apiConfig)
     if let instance = instances[instanceKey] {