diff --git a/src/print.c b/src/print.c
index 8e4a05fe3af..a5f1f97907f 100644
--- a/src/print.c
+++ b/src/print.c
@@ -598,6 +598,15 @@ to make it write to the debugging output.\n")
   
   return character;
 }
+
+/* This is the interface for debugging printing.  */
+
+void
+debug_print (arg)
+     Lisp_Object arg;
+{
+  Fprin1 (arg, Qexternal_debugging_output);
+}
 
 #ifdef LISP_FLOAT_TYPE