diff --git a/src/coding.h b/src/coding.h
index 00371e1fe633622a01a6c060779895b3e860a9cf..7ac022e942d34d9a0625cfacde7fdc78f0091ce6 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -390,6 +390,7 @@ extern int conversion_buffer_size;
 extern char *conversion_buffer, *get_conversion_buffer ();
 extern Lisp_Object Fcheck_coding_system ();
 extern Lisp_Object Qcoding_system, Qeol_type, Qcoding_category_index;
+extern Lisp_Object Qemacs_mule;
 extern Lisp_Object Qbuffer_file_coding_system;
 extern Lisp_Object Vcoding_category_list;