diff --git a/include/decl.h b/include/decl.h
index 1d6882214..745a00ff0 100644
--- a/include/decl.h
+++ b/include/decl.h
@@ -499,6 +499,7 @@ struct cmd {
     const char *alphadirchars; /* same as dirchars if !numpad */
     const struct ext_func_tab *commands[256]; /* indexed by input character */
     char spkeys[NUM_NHKF];
+    char extcmd_char;      /* key that starts an extended command ('#') */
 };
 
 
diff --git a/include/extern.h b/include/extern.h
index 46d5a326b..e6786e8ea 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -260,6 +260,8 @@ extern void cmdq_clear(void);
 extern char pgetchar(void);
 extern void pushch(char);
 extern void savech(char);
+extern void savech_extcmd(const char *, boolean);
+extern char extcmd_initiator(void);
 extern int doextcmd(void);
 extern struct ext_func_tab *extcmds_getentry(int);
 extern int extcmds_match(const char *, int, int **);
diff --git a/src/cmd.c b/src/cmd.c
index d796ebc36..f1911c449 100644
--- a/src/cmd.c
+++ b/src/cmd.c
@@ -400,6 +400,43 @@ savech(char ch)
     return;
 }
 
+/* perform savech() for the characters of an extended command name;
+   inserts the '#' first because rhack() no longer does that one
+   while processing do_extcmd();
+   'str' might be the full command name or maybe just enough to be
+   unambiguous depending on how the interface handles that--we don't
+   care as long as ^A feeds back what the interface expects to see */
+void
+savech_extcmd(const char *str, boolean addnewline)
+{
+    int j;
+
+    /* this debuging line might be immediately erased and need ^P to read */
+    debugpline1("savech_extcmd(\"%s\")", str);
+
+    if (!g.in_doagain && strcmp(str, "repeat")) {
+        uchar c = (g.shead > 0) ? (uchar) (g.saveq[g.shead - 1] & 0xff) : 0;
+
+        /* reset saveq unless it holds a prefix */
+        if (!c || !g.Cmd.commands[c]
+            || (g.Cmd.commands[c]->flags & PREFIXCMD) == 0)
+            savech(0);
+
+        savech(g.Cmd.extcmd_char);
+        for (j = 0; str[j]; j++)
+            savech(str[j]);
+        if (addnewline)
+            savech('\n');
+    }
+}
+
+/* '#' or whatever has been bound to do_extcmd() in its place */
+char
+extcmd_initiator(void)
+{
+    return g.Cmd.extcmd_char;
+}
+
 static boolean
 can_do_extcmd(const struct ext_func_tab *extcmd)
 {
@@ -3683,7 +3720,8 @@ reset_commands(boolean initial)
         if (backed_dir_cmd) {
             for (dir = 0; dir < N_DIRS; dir++) {
                 for (mode = 0; mode < N_MOVEMODES; mode++) {
-                    g.Cmd.commands[back_dir_key[dir][mode]] = back_dir_cmd[dir][mode];
+                    g.Cmd.commands[back_dir_key[dir][mode]]
+                        = back_dir_cmd[dir][mode];
                 }
             }
         }
@@ -3766,7 +3804,8 @@ reset_commands(boolean initial)
                 else if (mode == MV_RUSH) di = M(di);
             }
             back_dir_key[dir][mode] = di;
-            back_dir_cmd[dir][mode] = (struct ext_func_tab *) g.Cmd.commands[di];
+            back_dir_cmd[dir][mode]
+                = (struct ext_func_tab *) g.Cmd.commands[di];
             g.Cmd.commands[di] = (struct ext_func_tab *) 0;
         }
     }
@@ -3776,15 +3815,17 @@ reset_commands(boolean initial)
     for (i = 0; i < N_DIRS; i++) {
         (void) bind_key_fn(g.Cmd.dirchars[i], move_funcs[i][MV_WALK]);
         if (!g.Cmd.num_pad) {
-            (void) bind_key_fn(highc(g.Cmd.dirchars[i]), move_funcs[i][MV_RUN]);
+            (void) bind_key_fn(highc(g.Cmd.dirchars[i]),
+                               move_funcs[i][MV_RUN]);
             (void) bind_key_fn(C(g.Cmd.dirchars[i]), move_funcs[i][MV_RUSH]);
         } else {
             /* M(number) works when altmeta is on */
             (void) bind_key_fn(M(g.Cmd.dirchars[i]), move_funcs[i][MV_RUN]);
-            /* can't bind highc() or C() of numbers. just use the 5 prefix. */
+            /* can't bind highc() or C() of digits. just use the 5 prefix. */
         }
     }
     update_rest_on_space();
+    g.Cmd.extcmd_char = cmd_from_func(doextcmd);
 }
 
 /* called when 'rest_on_space' is toggled, also called by reset_commands()
@@ -5170,7 +5211,12 @@ parse(void)
     } else if (g.in_doagain) {
         g.command_count = g.last_command_count;
     } else if (foo && g.Cmd.commands[foo & 0xff]
-               && g.Cmd.commands[foo & 0xff]->ef_funct == do_repeat) {
+               /* these shouldn't go into the do-again buffer */
+               && (g.Cmd.commands[foo & 0xff]->ef_funct == do_repeat
+                   || g.Cmd.commands[foo & 0xff]->ef_funct == doprev_message
+                   /* this one might get put into the do-again buffer but
+                      only if the interface code tells the core to do it */
+                   || g.Cmd.commands[foo & 0xff]->ef_funct == doextcmd)) {
         /* g.command_count will be set again when we
            re-enter with g.in_doagain set true */
         g.command_count = g.last_command_count;
diff --git a/win/Qt/qt_xcmd.cpp b/win/Qt/qt_xcmd.cpp
index 8755897a6..fff29e649 100644
--- a/win/Qt/qt_xcmd.cpp
+++ b/win/Qt/qt_xcmd.cpp
@@ -581,7 +581,15 @@ int NetHackQtExtCmdRequestor::get()
     }
     if (result() == xcmdNone)
 	exec();
-    return result() - 1;
+
+    int ret = result() - 1;
+    if (!::g.in_doagain) {
+        if (ret >= 0)
+            savech_extcmd(::extcmdlist[ret].ef_txt, FALSE);
+        else
+            savech(0);
+    }
+    return ret;
 }
 
 // Enable only buttons that match the current prompt string
diff --git a/win/X11/winmisc.c b/win/X11/winmisc.c
index 644d1cd3f..2a027b094 100644
--- a/win/X11/winmisc.c
+++ b/win/X11/winmisc.c
@@ -1556,8 +1556,13 @@ X11_get_ext_cmd(void)
     /* The callbacks will enable the event loop exit. */
     (void) x_event(EXIT_ON_EXIT);
 
-    if (extended_cmd_selected < 0)
+    if (extended_cmd_selected < 0) {
+        if (!g.in_doagain)
+            savech(0);
         return -1;
+    }
+    if (!g.in_doagain)
+        savech_extcmd(command_list[extended_cmd_selected], TRUE);
     return command_indx[extended_cmd_selected];
 }
 
diff --git a/win/curses/cursdial.c b/win/curses/cursdial.c
index b448fc771..f380fc5d4 100644
--- a/win/curses/cursdial.c
+++ b/win/curses/cursdial.c
@@ -437,7 +437,7 @@ curses_ext_cmd(void)
 
         curs_set(1);
         wrefresh(extwin);
-        letter = getch();
+        letter = pgetchar(); /* pgetchar(cmd.c) implements do-again */
         curs_set(0);
         prompt_width = (int) strlen(cur_choice);
         matches = 0;
@@ -494,8 +494,23 @@ curses_ext_cmd(void)
     curses_destroy_win(extwin);
     if (extwin2)
         curses_destroy_win(extwin2);
-    if (ret == -1 && *cur_choice)
-        pline("%s: unknown extended command.", cur_choice);
+
+    if (ret != -1) {
+        if (!g.in_doagain)
+            savech_extcmd(cur_choice, TRUE);
+    } else {
+        char extcmd_char = extcmd_initiator();
+
+        if (*cur_choice)
+            pline("%s%s: unknown extended command.",
+                  visctrl(extcmd_char), cur_choice);
+
+        if (!g.in_doagain) {
+            savech(0); /* reset do-again buffer */
+            if (letter != '\033')
+                savech(extcmd_char);
+        }
+    }
     return ret;
 }
 
diff --git a/win/tty/getline.c b/win/tty/getline.c
index f94359bdc..98d1461d2 100644
--- a/win/tty/getline.c
+++ b/win/tty/getline.c
@@ -271,6 +271,8 @@ tty_get_ext_cmd(void)
     char buf[BUFSZ];
     int nmatches;
     int *ecmatches;
+    boolean (*no_hook)(char *base) = (boolean (*)(char *)) 0;
+    char extcmd_char[2];
 
     if (iflags.extmenu)
         return extcmd_via_menu();
@@ -282,27 +284,24 @@ tty_get_ext_cmd(void)
      *                      ? ext_cmd_getlin_hook
      *                      : (getlin_hook_proc) 0);
      */
+    extcmd_char[0] = extcmd_initiator(), extcmd_char[1] = '\0';
     buf[0] = '\0';
-    hooked_tty_getlin("#", buf, g.in_doagain ? (getlin_hook_proc) 0
-                                           : ext_cmd_getlin_hook);
+    hooked_tty_getlin(extcmd_char, buf,
+                      !g.in_doagain ? ext_cmd_getlin_hook : no_hook);
     (void) mungspaces(buf);
-    if (buf[0] == 0 || buf[0] == '\033')
-        return -1;
-
-    nmatches = extcmds_match(buf, ECM_IGNOREAC|ECM_EXACTMATCH, &ecmatches);
-
-    if (!g.in_doagain) {
-        int j;
-        for (j = 0; buf[j]; j++)
-            savech(buf[j]);
-        savech('\n');
-    }
 
+    nmatches = (buf[0] == '\0' || buf[0] == '\033') ? -1
+              : extcmds_match(buf, ECM_IGNOREAC | ECM_EXACTMATCH, &ecmatches);
     if (nmatches != 1) {
-        pline("%s: unknown extended command.", buf);
+        if (nmatches != -1)
+            pline("%s%.60s: unknown extended command.",
+                  visctrl(extcmd_char[0]), buf);
+        savech(0); /* reset do-again buffer */
+        savech(extcmd_char[0]);
         return -1;
     }
 
+    savech_extcmd(buf, TRUE); /* savech() for extcmd_char+buf[...]+'\n' */
     return ecmatches[0];
 }
 
diff --git a/win/win32/mswproc.c b/win/win32/mswproc.c
index 912078033..ba9bb97d8 100644
--- a/win/win32/mswproc.c
+++ b/win/win32/mswproc.c
@@ -1750,12 +1750,12 @@ int get_ext_cmd(void)
 int
 mswin_get_ext_cmd(void)
 {
+    char cmd[BUFSZ];
     int ret;
     logDebug("mswin_get_ext_cmd()\n");
 
     if (!iflags.wc_popup_dialog) {
         char c;
-        char cmd[BUFSZ];
         int i, len;
         int createcaret;
 
@@ -1784,7 +1784,8 @@ mswin_get_ext_cmd(void)
                         break;
 
                 if (extcmdlist[i].ef_txt == (char *) 0) {
-                    pline("%s: unknown extended command.", cmd);
+                    pline("%s%s: unknown extended command.",
+                          visctrl(extcmd_initiator()), cmd);
                     i = -1;
                 }
                 break;
@@ -1825,13 +1826,22 @@ mswin_get_ext_cmd(void)
         createcaret = 0;
         SendMessage(mswin_hwnd_from_winid(WIN_MESSAGE), WM_MSNH_COMMAND,
                     (WPARAM) MSNH_MSG_CARET, (LPARAM) &createcaret);
-        return i;
+        ret = i;
     } else {
-        if (mswin_ext_cmd_window(&ret) == IDCANCEL)
-            return -1;
+        cmd[0] = '\0';
+        if (mswin_ext_cmd_window(&ret) != IDCANCEL)
+            Strcpy(cmd, extcmdlist[ret].ef_txt);
         else
-            return ret;
+            ret = -1;
     }
+
+    if (!g.in_doagain) {
+        if (ret >= 0)
+            savech_extcmd(cmd, TRUE);
+        else
+            savech(0);
+    }
+    return ret;
 }
 
 /*