diff --git a/src/nostalgia/modules/core/src/gba/panic.cpp b/src/nostalgia/modules/core/src/gba/panic.cpp
index 67eaa702..728e3b00 100644
--- a/src/nostalgia/modules/core/src/gba/panic.cpp
+++ b/src/nostalgia/modules/core/src/gba/panic.cpp
@@ -32,8 +32,7 @@ void panic(const char *file, int line, const char *panicMsg, ox::Error const&err
 	std::ignore = initConsole(*ctx);
 	setBgStatus(*ctx, 0, true);
 	clearBg(*ctx, 0);
-	ox::IString<23> serr = "Error code: ";
-	serr += static_cast<int64_t>(err);
+	auto const serr = ox::sfmt<ox::IString<23>>("Error code: {}", static_cast<int64_t>(err));
 	puts(*ctx, 32 + 1,  1, "SADNESS...");
 	puts(*ctx, 32 + 1,  4, "UNEXPECTED STATE:");
 	puts(*ctx, 32 + 2,  6, panicMsg);
diff --git a/src/nostalgia/modules/core/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp b/src/nostalgia/modules/core/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
index a2c91f0a..6f68e705 100644
--- a/src/nostalgia/modules/core/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
+++ b/src/nostalgia/modules/core/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
@@ -8,6 +8,8 @@
 #include <ox/std/point.hpp>
 #include <keel/media.hpp>
 
+#include "ox/std/buffer.hpp"
+#include "ox/std/cstrops.hpp"
 #include "tilesheeteditor-imgui.hpp"
 
 namespace nostalgia::core {
@@ -440,7 +442,9 @@ void TileSheetEditorImGui::drawPaletteSelector() noexcept {
 				ImGui::PushID(static_cast<int>(i));
 				// Column: color idx
 				ImGui::TableNextColumn();
-				auto const label = ox::IString<8>() + (i + 1);
+				ox::IString<8> label;
+				ox::CharBuffWriter w(label.data(), label.bytes());
+				std::ignore = ox::writeItoa(i + 1, w);
 				auto const rowSelected = i == m_view.palIdx();
 				if (ImGui::Selectable(label.c_str(), rowSelected, ImGuiSelectableFlags_SpanAllColumns)) {
 					m_view.setPalIdx(i);