diff --git a/kernel/include/sortix/kernel/log.h b/kernel/include/sortix/kernel/log.h
index efa0d742..986c5c03 100644
--- a/kernel/include/sortix/kernel/log.h
+++ b/kernel/include/sortix/kernel/log.h
@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
 
     This file is part of Sortix.
 
@@ -90,6 +90,7 @@ inline size_t PrintData(const void* ptr, size_t size)
 	return device_callback(device_pointer, (const char*) ptr, size);
 }
 
+__attribute__((format(printf, 1, 2)))
 inline size_t PrintF(const char* format, ...)
 {
 	va_list list;
@@ -99,6 +100,7 @@ inline size_t PrintF(const char* format, ...)
 	return result;
 }
 
+__attribute__((format(printf, 1, 0)))
 inline size_t PrintFV(const char* format, va_list list)
 {
 	return vprintf_callback(device_callback, device_pointer, format, list);
diff --git a/kernel/include/sortix/kernel/panic.h b/kernel/include/sortix/kernel/panic.h
index 79995b9c..4fd77663 100644
--- a/kernel/include/sortix/kernel/panic.h
+++ b/kernel/include/sortix/kernel/panic.h
@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2013.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2013, 2014.
 
     This file is part of Sortix.
 
@@ -29,7 +29,7 @@ namespace Sortix {
 
 extern "C" __attribute__((noreturn)) void HaltKernel();
 extern "C" __attribute__((noreturn)) void Panic(const char* error);
-extern "C" __attribute__((noreturn)) void PanicF(const char* format, ...);
+extern "C" __attribute__((noreturn, format(printf, 1, 2))) void PanicF(const char* format, ...);
 extern "C" void WaitForInterrupt();
 
 } // namespace Sortix