diff --git a/src/channel.c b/src/channel.c
index 504d6b6..40a3e95 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -5836,4 +5836,38 @@
     return 1;
 }
 
+    void
+invoke_prompt_callback(void)
+{
+    typval_T	rettv;
+    int		dummy;
+    typval_T	argv[2];
+    char_u	*text;
+    char_u	*prompt;
+    linenr_T	lnum = curbuf->b_ml.ml_line_count;
+
+    // Add a new line for the prompt before invoking the callback, so that
+    // text can always be inserted above the last line.
+    ml_append(lnum, (char_u  *)"", 0, FALSE);
+    curwin->w_cursor.lnum = lnum + 1;
+    curwin->w_cursor.col = 0;
+
+    if (curbuf->b_prompt_callback == NULL)
+	return;
+    text = ml_get(lnum);
+    prompt = prompt_text();
+    if (STRLEN(text) >= STRLEN(prompt))
+	text += STRLEN(prompt);
+    argv[0].v_type = VAR_STRING;
+    argv[0].vval.v_string = vim_strsave(text);
+    argv[1].v_type = VAR_UNKNOWN;
+
+    call_func(curbuf->b_prompt_callback,
+	      (int)STRLEN(curbuf->b_prompt_callback),
+	      &rettv, 1, argv, NULL, 0L, 0L, &dummy, TRUE,
+	      curbuf->b_prompt_partial, NULL);
+    clear_tv(&argv[0]);
+    clear_tv(&rettv);
+}
+
 #endif /* FEAT_JOB_CHANNEL */