diff --git a/src/process.c b/src/process.c
index 08cb810ec13..bdbe8d96064 100644
--- a/src/process.c
+++ b/src/process.c
@@ -6227,7 +6227,15 @@ read_process_output (Lisp_Object proc, int channel)
      friends don't expect current-buffer to be changed from under them.  */
   record_unwind_current_buffer ();
 
-  read_and_dispose_of_process_output (p, chars, nbytes, coding);
+  if (p->filter == Qinternal_default_process_filter)
+    {
+      Lisp_Object text;
+      decode_coding_c_string (coding, (unsigned char *) chars, nbytes, Qt);
+      text = coding->dst_object;
+      Finternal_default_process_filter (proc, text);
+    }
+  else
+    read_and_dispose_of_process_output (p, chars, nbytes, coding);
 
   /* Handling the process output should not deactivate the mark.  */
   Vdeactivate_mark = odeactivate;