diff --git a/gui/libui/src/Font.cpp b/gui/libui/src/Font.cpp
index 0534680c..12021d68 100644
--- a/gui/libui/src/Font.cpp
+++ b/gui/libui/src/Font.cpp
@@ -7,7 +7,7 @@
  *
  */
 
-#include <luna/String.h>
+#include <luna/RefString.h>
 #include <os/File.h>
 #include <ui/Font.h>
 
@@ -49,8 +49,8 @@ namespace ui
 
     Result<SharedPtr<Font>> Font::load_builtin(StringView name, FontWeight weight)
     {
-        auto path = TRY(String::format("/usr/share/fonts/%s-%s.psf"_sv, name.chars(),
-                                       weight == FontWeight::Bold ? "Bold" : "Regular"));
+        auto path = TRY(RefString::format("/usr/share/fonts/%s-%s.psf"_sv, name.chars(),
+                                          weight == FontWeight::Bold ? "Bold" : "Regular"));
 
         return load(path.view());
     }