diff --git a/kernel/debug.h b/kernel/debug.h
index e25605e0c..e9de2a5ca 100644
--- a/kernel/debug.h
+++ b/kernel/debug.h
@@ -67,4 +67,10 @@
 #define vmassert(t) { }
 #endif
 
+#define NOT_REACHABLE(__x) do {						\
+	kprintf("NOT_REACHABLE at %s:%d\n", __FILE__, __LINE__);	\
+	minix_panic("execution at an unexpected location\n", NO_NUM);	\
+	for(;;);							\
+} while(0)
+
 #endif /* DEBUG_H */
diff --git a/kernel/main.c b/kernel/main.c
index b847b2bef..1f63e08ac 100755
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -206,6 +206,7 @@ PUBLIC void main()
   FIXME("PROC check enabled");
 #endif
   restart();
+  NOT_REACHABLE();
 }
 
 /*===========================================================================*