diff --git a/src/apprt/gtk/class/surface.zig b/src/apprt/gtk/class/surface.zig
index 527a6136b..087f2d286 100644
--- a/src/apprt/gtk/class/surface.zig
+++ b/src/apprt/gtk/class/surface.zig
@@ -523,7 +523,7 @@ pub const Surface = extern struct {
         inspector: ?*InspectorWindow = null,
 
         /// Number of siblings related to this surface. This is used for
-        /// the unfocused-split-* options which are only applied when ther is
+        /// the unfocused-split-* options which are only applied when their is
         /// more than once surface (split) in a tab
         n_siblings: u64 = 0,