LibJS: Use RTTI for inheritance checks

This replaces the hand-rolled string-based inheritance check tech.

1 files changed, 1 insertions, 1 deletions

diff --git a/Applications/Spreadsheet/JSIntegration.cpp b/Applications/Spreadsheet/JSIntegration.cpp
index a10d8a884d..12a249593e 100644
--- a/Applications/Spreadsheet/JSIntegration.cpp
+++ b/Applications/Spreadsheet/JSIntegration.cpp
@@ -419,7 +419,7 @@ JS_DEFINE_NATIVE_FUNCTION(WorkbookObject::sheet)
     if (!this_object)
         return {};
 
-    if (!this_object->inherits("WorkbookObject")) {
+    if (!is<WorkbookObject>(this_object)) {
         vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotA, "WorkbookObject");
         return {};
     }