diff --git a/Kernel/KBufferBuilder.h b/Kernel/KBufferBuilder.h
index 106d9d9155..4ab6b1527d 100644
--- a/Kernel/KBufferBuilder.h
+++ b/Kernel/KBufferBuilder.h
@@ -33,7 +33,9 @@ public:
     {
         // FIXME: This is really not the way to go about it, but vformat expects a
         //        StringBuilder. Why does this class exist anyways?
-        append(String::formatted(fmtstr.view(), parameters...));
+        StringBuilder builder;
+        vformat(builder, fmtstr.view(), AK::VariadicFormatParams { parameters... });
+        append_bytes(builder.string_view().bytes());
     }
 
     bool flush();