diff --git a/src/debug.cpp b/src/debug.cpp
index 0c3d8b6..940991d 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -6,6 +6,8 @@
 
 #include <tonc.h>
 
+#include <mtl/string.hpp>
+
 namespace debug {
 /**
  * \brief MGBA debug registers and constants
@@ -26,15 +28,14 @@ static volatile uint16_t* flags = reinterpret_cast<uint16_t*>(0x4FFF700);
 /**
  * \brief MGBA debug string register.
  *
- * Max length of 0x100 (256)
+ * Max length of 0x100 (256) including null terminator.
  */
-static char* string = reinterpret_cast<char*>(0x4FFF600);
-constexpr size_t string_len = 0x100;
+static mtl::string_ext string(reinterpret_cast<char*>(0x4FFF600), 256);
 }; // namespace reg
 
 
 void puts(const char* msg, level lvl) {
-	std::strncpy(reg::string, msg, reg::string_len);
+	reg::string = msg;
 	*reg::flags = (lvl) | 0x100;
 }