diff --git a/DevLog/Infra/Service/SocialLogin/GithubAuthenticationService.swift b/DevLog/Infra/Service/SocialLogin/GithubAuthenticationService.swift
index 05b6da5..22e18dd 100644
--- a/DevLog/Infra/Service/SocialLogin/GithubAuthenticationService.swift
+++ b/DevLog/Infra/Service/SocialLogin/GithubAuthenticationService.swift
@@ -18,6 +18,7 @@ final class GithubAuthenticationService: NSObject, AuthenticationService {
     private let messaging = Messaging.messaging()
     private var user: User? { Auth.auth().currentUser }
     private let providerID = AuthProviderID.gitHub
+    private let provider = TopViewControllerProvider()
     private let logger = Logger(category: "GithubAuthService")
 
     func signIn() async throws -> AuthenticationDataResponse {
@@ -143,6 +144,7 @@ final class GithubAuthenticationService: NSObject, AuthenticationService {
         }
     }
 
+    @MainActor
     func requestAuthorizationCode() async throws -> String {
         guard let clientID = Bundle.main.object(forInfoDictionaryKey: "GITHUB_CLIENT_ID") as? String,
               let redirectURL = Bundle.main.object(forInfoDictionaryKey: "APP_REDIRECT_URL") as? String,
@@ -248,12 +250,7 @@ final class GithubAuthenticationService: NSObject, AuthenticationService {
 
 extension GithubAuthenticationService: ASWebAuthenticationPresentationContextProviding {
     func presentationAnchor(for session: ASWebAuthenticationSession) -> ASPresentationAnchor {
-        guard let window = UIApplication.shared.connectedScenes
-            .flatMap({ ($0 as? UIWindowScene)?.windows ?? [] })
-            .first(where: { $0.isKeyWindow }) else {
-                return ASPresentationAnchor()
-        }
-        return window
+        return provider.keyWindow() ?? ASPresentationAnchor()
     }
 
     struct GitHubUser: Codable {
diff --git a/DevLog/Infra/Service/SocialLogin/GoogleAuthenticationService.swift b/DevLog/Infra/Service/SocialLogin/GoogleAuthenticationService.swift
index 5798975..55c4b1f 100644
--- a/DevLog/Infra/Service/SocialLogin/GoogleAuthenticationService.swift
+++ b/DevLog/Infra/Service/SocialLogin/GoogleAuthenticationService.swift
@@ -126,35 +126,3 @@ final class GoogleAuthenticationService: AuthenticationService {
     }
 
 }
-
-final class TopViewControllerProvider {
-    @MainActor
-    func topViewController() -> UIViewController? {
-        let keyWindow = UIApplication.shared.connectedScenes
-            .compactMap { $0 as? UIWindowScene }
-            .flatMap { $0.windows }
-            .first { $0.isKeyWindow }
-
-        let rootController = keyWindow?.rootViewController
-
-        return topViewController(controller: rootController)
-    }
-
-    @MainActor
-    private func topViewController(controller: UIViewController?) -> UIViewController? {
-        if let navigationController = controller as? UINavigationController {
-            return topViewController(controller: navigationController.visibleViewController)
-        }
-
-        if let tabController = controller as? UITabBarController,
-           let selectedController = tabController.selectedViewController {
-            return topViewController(controller: selectedController)
-        }
-
-        if let presentedController = controller?.presentedViewController {
-            return topViewController(controller: presentedController)
-        }
-
-        return controller
-    }
-}
diff --git a/DevLog/Infra/Util/TopViewControllerProvider.swift b/DevLog/Infra/Util/TopViewControllerProvider.swift
new file mode 100644
index 0000000..ba5304c
--- /dev/null
+++ b/DevLog/Infra/Util/TopViewControllerProvider.swift
@@ -0,0 +1,46 @@
+//
+//  TopViewControllerProvider.swift
+//  DevLog
+//
+//  Created by 최윤진 on 2/12/26.
+//
+
+import UIKit
+
+final class TopViewControllerProvider {
+    @MainActor
+    func topViewController() -> UIViewController? {
+        guard let keyWindow = keyWindow() else {
+            return nil
+        }
+        
+        let rootController = keyWindow.rootViewController
+        return topViewController(controller: rootController)
+    }
+    
+    @MainActor
+    func keyWindow() -> UIWindow? {
+        return UIApplication.shared.connectedScenes
+            .compactMap { $0 as? UIWindowScene }
+            .flatMap { $0.windows }
+            .first { $0.isKeyWindow }
+    }
+
+    @MainActor
+    private func topViewController(controller: UIViewController?) -> UIViewController? {
+        if let navigationController = controller as? UINavigationController {
+            return topViewController(controller: navigationController.visibleViewController)
+        }
+
+        if let tabController = controller as? UITabBarController,
+           let selectedController = tabController.selectedViewController {
+            return topViewController(controller: selectedController)
+        }
+
+        if let presentedController = controller?.presentedViewController {
+            return topViewController(controller: presentedController)
+        }
+
+        return controller
+    }
+}