diff --git a/Source/AppAuth/iOS/OIDExternalUserAgentIOS.h b/Source/AppAuth/iOS/OIDExternalUserAgentIOS.h
index ae0773c69..12abc203c 100644
--- a/Source/AppAuth/iOS/OIDExternalUserAgentIOS.h
+++ b/Source/AppAuth/iOS/OIDExternalUserAgentIOS.h
@@ -34,7 +34,7 @@ NS_ASSUME_NONNULL_BEGIN
 API_UNAVAILABLE(macCatalyst)
 @interface OIDExternalUserAgentIOS : NSObject<OIDExternalUserAgent>
 
-- (nullable instancetype)init API_AVAILABLE(ios(11))
+- (null_unspecified instancetype)init API_AVAILABLE(ios(11))
     __deprecated_msg("This method will not work on iOS 13, use "
                      "initWithPresentingViewController:presentingViewController");
 
diff --git a/Source/AppAuth/iOS/OIDExternalUserAgentIOS.m b/Source/AppAuth/iOS/OIDExternalUserAgentIOS.m
index eab7aa3cb..4a8cda0a3 100644
--- a/Source/AppAuth/iOS/OIDExternalUserAgentIOS.m
+++ b/Source/AppAuth/iOS/OIDExternalUserAgentIOS.m
@@ -55,7 +55,7 @@ @implementation OIDExternalUserAgentIOS {
 #pragma clang diagnostic pop
 }
 
-- (nullable instancetype)init {
+- (null_unspecified instancetype)init {
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wnonnull"
   return [self initWithPresentingViewController:nil];