diff --git a/src/option.h b/src/option.h
index 2d1ca2c..646056b 100644
--- a/src/option.h
+++ b/src/option.h
@@ -1321,4 +1321,6 @@
 // Value for b_p_ul indicating the global value must be used.
 #define NO_LOCAL_UNDOLEVEL (-123456)
 
+#define ERR_BUFLEN 80
+
 #endif // _OPTION_H_