diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index fdf6fa0..f90588a 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -81,6 +81,12 @@
 	do { printk(arg); __WARN_TAINT(taint); } while (0)
 #endif
 
+/* used internally by panic.c */
+struct warn_args;
+
+void __warn(const char *file, int line, void *caller, unsigned taint,
+	    struct pt_regs *regs, struct warn_args *args);
+
 #ifndef WARN_ON
 #define WARN_ON(condition) ({						\
 	int __ret_warn_on = !!(condition);				\