diff --git a/kernel/src/arch/Serial.cpp b/kernel/src/arch/Serial.cpp
index db860f2c..9a00a751 100644
--- a/kernel/src/arch/Serial.cpp
+++ b/kernel/src/arch/Serial.cpp
@@ -1,4 +1,5 @@
 #include "arch/Serial.h"
+#include "arch/CPU.h"
 #include <Format.h>
 
 namespace Serial
@@ -33,4 +34,16 @@ namespace Serial
         va_end(ap);
         return rc;
     }
+}
+
+static bool g_check_already_failed = false;
+
+_noreturn bool __check_failed(const char* file, const char* line, const char* func, const char* expr)
+{
+    if (!g_check_already_failed)
+    { // Avoid endlessly failing when trying to report a failed check.
+        g_check_already_failed = true;
+        Serial::printf("ERROR: Check failed at %s:%s, in %s: %s\n", file, line, func, expr);
+    }
+    CPU::efficient_halt();
 }
\ No newline at end of file
diff --git a/luna/CMakeLists.txt b/luna/CMakeLists.txt
index bfb5d3f7..54f2f78d 100644
--- a/luna/CMakeLists.txt
+++ b/luna/CMakeLists.txt
@@ -6,6 +6,7 @@ set(FREESTANDING_SOURCES
 
 set(SOURCES
     ${FREESTANDING_SOURCES}
+    Check.cpp
 )
 
 add_library(luna-freestanding ${FREESTANDING_SOURCES})
diff --git a/luna/Check.cpp b/luna/Check.cpp
new file mode 100644
index 00000000..e464ca86
--- /dev/null
+++ b/luna/Check.cpp
@@ -0,0 +1,6 @@
+#include <Attributes.h>
+
+_weak _noreturn bool __check_failed(const char*, const char*, const char*, const char*)
+{
+    __builtin_trap();
+}
\ No newline at end of file
diff --git a/luna/Check.h b/luna/Check.h
index f8c4fd13..1e24fb66 100644
--- a/luna/Check.h
+++ b/luna/Check.h
@@ -1,22 +1,9 @@
 #pragma once
-#ifdef IN_MOON
-#include "arch/Serial.h"
+#include <Attributes.h>
 
-[[noreturn]] inline bool __check_failed(const char* string)
-{
-    Serial::print("CHECK FAILED: ");
-    Serial::println(string);
-    for (;;)
-        ;
-}
-#else
-[[noreturn]] inline bool __check_failed(const char*)
-{
-    __builtin_trap();
-}
-#endif
+extern _noreturn bool __check_failed(const char* file, const char* line, const char* func, const char* expr);
 
 #define STRINGIZE(x) #x
 #define STRINGIZE_VALUE_OF(x) STRINGIZE(x)
 
-#define check(expr) (expr) || __check_failed("at " __FILE__ ":" STRINGIZE_VALUE_OF(__LINE__) ": " #expr)
\ No newline at end of file
+#define check(expr) (expr) || __check_failed(__FILE__, STRINGIZE_VALUE_OF(__LINE__), __PRETTY_FUNCTION__, #expr)