diff --git a/src/appkit.cs b/src/appkit.cs
index a4f7227de1f3..b97be9410982 100644
--- a/src/appkit.cs
+++ b/src/appkit.cs
@@ -20503,8 +20503,23 @@ interface NSToolbarItem : NSCopying, NSMenuItemValidation, NSValidatedUserInterf
 		[Export ("maxSize")]
 		CGSize MaxSize { get; set; }
 
+#if XAMCORE_5_0
+		[Export ("visibilityPriority")]
+		NSToolbarItemVisibilityPriority VisibilityPriority { get; set; }
+#else
+		/// <summary>Indicate which toolbar items should be kept when the toolbar space is limited.</summary>
+		/// <remarks>
+		///   <para>The valid values come from the <see cref="NSToolbarItemVisibilityPriority" /> enum, and they can be referenced as follows:</para>
+		///   <example>
+		///     <code lang="csharp lang-csharp"><![CDATA[
+		/// NSToolbarItem item = GetItem ();
+		/// item.VisibilityPriority = (nint) (long) NSToolbarItemVisibilityPriority.High;
+		/// ]]></code>
+		///   </example>
+		/// </remarks>
 		[Export ("visibilityPriority")]
 		nint VisibilityPriority { get; set; }
+#endif
 
 		[Export ("autovalidates")]
 		bool Autovalidates { get; set; }
@@ -28838,4 +28853,12 @@ interface NSViewContentSelectionInfo {
 		[Export ("selectionAnchorRect")]
 		CGRect /* NSRect */ SelectionAnchorRect { get; }
 	}
+
+	[Native]
+	enum NSToolbarItemVisibilityPriority : long {
+		Standard = 0,
+		Low = -1000,
+		High = 1000,
+		User = 2000,
+	}
 }
diff --git a/tests/cecil-tests/Documentation.KnownFailures.txt b/tests/cecil-tests/Documentation.KnownFailures.txt
index 56aca8bf163d..17d3e16881ca 100644
--- a/tests/cecil-tests/Documentation.KnownFailures.txt
+++ b/tests/cecil-tests/Documentation.KnownFailures.txt
@@ -2869,6 +2869,10 @@ F:AppKit.NSToolbarItemGroupControlRepresentation.Expanded
 F:AppKit.NSToolbarItemGroupSelectionMode.Momentary
 F:AppKit.NSToolbarItemGroupSelectionMode.SelectAny
 F:AppKit.NSToolbarItemGroupSelectionMode.SelectOne
+F:AppKit.NSToolbarItemVisibilityPriority.High
+F:AppKit.NSToolbarItemVisibilityPriority.Low
+F:AppKit.NSToolbarItemVisibilityPriority.Standard
+F:AppKit.NSToolbarItemVisibilityPriority.User
 F:AppKit.NSToolbarSizeMode.Default
 F:AppKit.NSToolbarSizeMode.Regular
 F:AppKit.NSToolbarSizeMode.Small
@@ -80962,6 +80966,7 @@ T:AppKit.NSToolbarImmovableItemIdentifiers
 T:AppKit.NSToolbarItemEventArgs
 T:AppKit.NSToolbarItemGroupControlRepresentation
 T:AppKit.NSToolbarItemGroupSelectionMode
+T:AppKit.NSToolbarItemVisibilityPriority
 T:AppKit.NSToolbarSizeMode
 T:AppKit.NSToolbarWillInsert
 T:AppKit.NSTouch_NSTouchBar
diff --git a/tests/xtro-sharpie/api-annotations-dotnet/common-AppKit.ignore b/tests/xtro-sharpie/api-annotations-dotnet/common-AppKit.ignore
index 6f9811c32731..d8151a01de31 100644
--- a/tests/xtro-sharpie/api-annotations-dotnet/common-AppKit.ignore
+++ b/tests/xtro-sharpie/api-annotations-dotnet/common-AppKit.ignore
@@ -16,3 +16,6 @@
 !missing-field! NSTypeIdentifierTransitInformationText not bound
 !missing-protocol! NSAnimatablePropertyContainer not bound
 !missing-selector! NSTouchBar::itemIdentifiers not bound
+
+# NSToolbarItemVisibilityPriority is a collection of constants we've bound as an enum.
+!unknown-native-enum! NSToolbarItemVisibilityPriority bound