diff --git a/Sources/BetterSafariView/WebAuthenticationSession/WebAuthenticationPresenter.swift b/Sources/BetterSafariView/WebAuthenticationSession/WebAuthenticationPresenter.swift
index ec664c6..bbe7552 100644
--- a/Sources/BetterSafariView/WebAuthenticationSession/WebAuthenticationPresenter.swift
+++ b/Sources/BetterSafariView/WebAuthenticationSession/WebAuthenticationPresenter.swift
@@ -179,7 +179,7 @@ extension WebAuthenticationPresenter {
             // MARK: ASWebAuthenticationPresentationContextProviding
             
             func presentationAnchor(for session: ASWebAuthenticationSession) -> ASPresentationAnchor {
-                return coordinator.view.window!
+                return coordinator.view.window ?? ASPresentationAnchor()
             }
         }