diff --git a/src/main.c b/src/main.c
index b92be4c..3d86796 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1025,6 +1025,17 @@
 	;
 }
 
+#if defined(FEAT_GUI) || defined(PROTO)
+/*
+ * If a --gui-dialog-file argument was given return the file name.
+ * Otherwise return NULL.
+ */
+    char_u *
+get_gui_dialog_file(void)
+{
+    return params.gui_dialog_file;
+}
+#endif
 
 // When TRUE in a safe state when starting to wait for a character.
 static int	was_safe = FALSE;
@@ -2009,6 +2020,7 @@
 				// "--log fname" start logging early
 				// "--nofork" don't fork
 				// "--not-a-term" don't warn for not a term
+				// "--gui-dialog-file fname" write dialog text
 				// "--ttyfail" exit if not a term
 				// "--noplugin[s]" skip plugins
 				// "--cmd <cmd>" execute cmd before vimrc
@@ -2052,6 +2064,12 @@
 		    p_lpl = FALSE;
 		else if (STRNICMP(argv[0] + argv_idx, "not-a-term", 10) == 0)
 		    parmp->not_a_term = TRUE;
+		else if (STRNICMP(argv[0] + argv_idx, "gui-dialog-file", 15)
+									 == 0)
+		{
+		    want_argument = TRUE;
+		    argv_idx += 15;
+		}
 		else if (STRNICMP(argv[0] + argv_idx, "ttyfail", 7) == 0)
 		    parmp->tty_fail = TRUE;
 		else if (STRNICMP(argv[0] + argv_idx, "cmd", 3) == 0)
@@ -2448,6 +2466,15 @@
 			parmp->pre_commands[parmp->n_pre_commands++] =
 							    (char_u *)argv[0];
 		    }
+		    // --gui-dialog-file fname
+		    if (argv[-1][2] == 'g')
+		    {
+			// without GUI ignore the argument
+#ifdef FEAT_GUI
+			parmp->gui_dialog_file = (char_u *)argv[0];
+#endif
+		    }
+
 		    // "--startuptime <file>" already handled
 		    // "--log <file>" already handled
 		    break;
@@ -3515,6 +3542,9 @@
 #endif
     main_msg(_("-T <terminal>\tSet terminal type to <terminal>"));
     main_msg(_("--not-a-term\t\tSkip warning for input/output not being a terminal"));
+#ifdef FEAT_GUI
+    main_msg(_("--gui-dialog-file {fname}  For testing: write dialog text"));
+#endif
     main_msg(_("--ttyfail\t\tExit if input or output is not a terminal"));
     main_msg(_("-u <vimrc>\t\tUse <vimrc> instead of any .vimrc"));
 #ifdef FEAT_GUI