diff --git a/source/Google/MobileAds/ApiDefinition.cs b/source/Google/MobileAds/ApiDefinition.cs
index d00b492de..fdb862e41 100644
--- a/source/Google/MobileAds/ApiDefinition.cs
+++ b/source/Google/MobileAds/ApiDefinition.cs
@@ -1005,6 +1005,29 @@ interface UnifiedNativeAdLoaderDelegate : AdLoaderDelegate {
 		void DidReceiveUnifiedNativeAd (AdLoader adLoader, NativeAd nativeAd);
 	}
 
+	interface ICustomNativeAdLoaderDelegate {
+	}
+
+	// @protocol GADCustomNativeAdLoaderDelegate <GADAdLoaderDelegate>
+#if NET
+		[Model]
+#else
+	[Model (AutoGeneratedName = true)]
+#endif
+	[Protocol]
+	[BaseType (typeof (NSObject), Name = "GADCustomNativeAdLoaderDelegate")]
+	interface CustomNativeAdLoaderDelegate : AdLoaderDelegate {
+		// @required - (NSArray<NSString *> * _Nonnull)customNativeAdFormatIDsForAdLoader: (GADAdLoader * _Nonnull)adLoader;
+		[Abstract]
+		[Export ("customNativeAdFormatIDsForAdLoader:")]
+		string[] CustomNativeAdFormatIdsForAdLoader (AdLoader adLoader);
+
+		// @required - (void)adLoader: (GADAdLoader * _Nonnull)adLoader didReceiveCustomNativeAd: (GADCustomNativeAd * _Nonnull)customNativeAd;
+		[Abstract]
+		[Export ("adLoader:didReceiveCustomNativeAd:")]
+		void AdLoader (AdLoader adLoader, CustomNativeAd customNativeAd);
+	}
+
 	// @interface GADNativeAdView : UIView
 	[BaseType (typeof (UIView), Name = "GADNativeAdView")]
 	interface NativeAdView {
@@ -1141,7 +1164,7 @@ interface CustomNativeAd {
 		// @property(atomic, copy, nullable) GADNativeAdCustomClickHandler customClickHandler;
 		[NullAllowed]
 		[Export ("customClickHandler", ArgumentSemantic.Copy)]
-		NativeAdCustomClickHandle CustomClickHandler { get; }
+		NativeAdCustomClickHandle CustomClickHandler { get; set; }
 
 		// @property(nonatomic, readonly, nullable) GADDisplayAdMeasurement *displayAdMeasurement;
 		[NullAllowed]