diff --git a/private/sdl_gpu_test/6_ui/app.cpp b/private/sdl_gpu_test/6_ui/app.cpp
index 9a8c620..63865de 100644
--- a/private/sdl_gpu_test/6_ui/app.cpp
+++ b/private/sdl_gpu_test/6_ui/app.cpp
@@ -81,7 +81,7 @@ void UIApp::init(const AppInitArgs& args)
     const unsigned posY = 100;
     for (const char chr : std::string_view("Dies ist ein Test-Text!"))
     {
-        const UVFontMapEntry& entry = uvFontMap.entries[chr];
+        const UVFontMapEntry& entry = uvFontMap.entries[chr < 0 ? '_' : chr];
         const UIVertex topLeft = {
             .pos = {posX + entry.xOffset, posY + entry.yOffset},
             .texcoord = {entry.uvX, entry.uvY}