diff --git a/CHANGELOG.md b/CHANGELOG.md
index be5bb8f0..a655cd2f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,10 @@
 * **initial-window-mode** option to `footrc`, that lets you control
   the initial mode for each newly spawned window: _windowed_,
   _maximized_ or _fullscreen_.
+* **app-id** option to `footrc`, that sets the _app-id_ property on
+  the Wayland window.
+* `--app-id` command line option, that sets the _app-id_ property on
+  the Wayland window.
 
 
 ### Changed
diff --git a/client.c b/client.c
index 7d188609..a7ba7e30 100644
--- a/client.c
+++ b/client.c
@@ -33,6 +33,7 @@ print_usage(const char *prog_name)
     printf("\n");
     printf("Options:\n");
     printf("  -t,--term=TERM                        value to set the environment variable TERM to (foot)\n"
+           "  -a,--app-id=ID                        window application ID (foot)\n"
            "     --maximized                        start in maximized mode\n"
            "     --fullscreen                       start in fullscreen mode\n"
            "     --login-shell                      start shell as a login shell\n"
@@ -49,18 +50,20 @@ main(int argc, char *const *argv)
     const char *const prog_name = argv[0];
 
     static const struct option longopts[] =  {
-        {"term",          required_argument, 0, 't'},
-        {"maximized",     no_argument,       0, 'm'},
-        {"fullscreen",    no_argument,       0, 'F'},
-        {"login-shell",   no_argument,       0, 'L'},
-        {"server-socket", required_argument, 0, 's'},
+        {"term",          required_argument, NULL, 't'},
+        {"app-id",        required_argument, NULL, 'a'},
+        {"maximized",     no_argument,       NULL, 'm'},
+        {"fullscreen",    no_argument,       NULL, 'F'},
+        {"login-shell",   no_argument,       NULL, 'L'},
+        {"server-socket", required_argument, NULL, 's'},
         {"log-colorize",  optional_argument, NULL, 'l'},
-        {"version",       no_argument,       0, 'v'},
-        {"help",          no_argument,       0, 'h'},
-        {NULL,            no_argument,       0,   0},
+        {"version",       no_argument,       NULL, 'v'},
+        {"help",          no_argument,       NULL, 'h'},
+        {NULL,            no_argument,       NULL,   0},
     };
 
     const char *term = "";
+    const char *app_id = "";
     const char *server_socket_path = NULL;
     enum log_colorize log_colorize = LOG_COLORIZE_AUTO;
     bool login_shell = false;
@@ -68,7 +71,7 @@ main(int argc, char *const *argv)
     bool fullscreen = false;
 
     while (true) {
-        int c = getopt_long(argc, argv, ":t:s:l::hv", longopts, NULL);
+        int c = getopt_long(argc, argv, ":t:a:s:l::hv", longopts, NULL);
         if (c == -1)
             break;
 
@@ -77,6 +80,10 @@ main(int argc, char *const *argv)
             term = optarg;
             break;
 
+        case 'a':
+            app_id = optarg;
+            break;
+
         case 'L':
             login_shell = true;
             break;
@@ -186,13 +193,14 @@ main(int argc, char *const *argv)
         } while (errno == ERANGE);
     }
     const uint16_t cwd_len = strlen(cwd) + 1;
-
     const uint16_t term_len = strlen(term) + 1;
+    const uint16_t app_id_len = strlen(app_id) + 1;
     uint32_t total_len = 0;
 
     /* Calculate total length */
     total_len += sizeof(cwd_len) + cwd_len;
     total_len += sizeof(term_len) + term_len;
+    total_len += sizeof(app_id_len) + app_id_len;
     total_len += sizeof(uint8_t);  /* maximized */
     total_len += sizeof(uint8_t);  /* fullscreen */
     total_len += sizeof(uint8_t);  /* login_shell */
@@ -225,6 +233,13 @@ main(int argc, char *const *argv)
         goto err;
     }
 
+    if (send(fd, &app_id_len, sizeof(app_id_len), 0) != sizeof(app_id_len) ||
+        send(fd, app_id, app_id_len, 0) != app_id_len)
+    {
+        LOG_ERRNO("failed to send app-id to server");
+        goto err;
+    }
+
     if (send(fd, &(uint8_t){maximized}, sizeof(uint8_t), 0) != sizeof(uint8_t)) {
         LOG_ERRNO("failed to send maximized");
         goto err;
diff --git a/completions/zsh/_foot b/completions/zsh/_foot
index 95e8d98e..8fcd21a4 100644
--- a/completions/zsh/_foot
+++ b/completions/zsh/_foot
@@ -5,6 +5,7 @@ _arguments \
     '(-c --config)'{-c,--config}'[path to configuration file (XDG_CONFIG_HOME/footrc)]:config:_files' \
     '(-f --font)'{-f,--font}'[font name and style in fontconfig format (monospace)]:font:->fonts' \
     '(-t --term)'{-t,--term}'[value to set the environment variable TERM to (foot)]:term:->terms' \
+    '(-a --app-id)'{-a,-app-id}'[value to set the window\'s app-id to (foot)]' \
     '--maximized[start in maximized mode]' \
     '--fullscreen[start in fullscreen mode]' \
     '--login-shell[start shell as a login shell]' \
diff --git a/completions/zsh/_footclient b/completions/zsh/_footclient
index 7f8c8009..d7d26db0 100644
--- a/completions/zsh/_footclient
+++ b/completions/zsh/_footclient
@@ -3,6 +3,7 @@
 _arguments \
     -s \
     '(-t --term)'{-t,--term}'[value to set the environment variable TERM to (foot)]:term:->terms' \
+    '(-a --app-id)'{-a,-app-id}'[value to set the window\'s app-id to (foot)]' \
     '--maximized[start in maximized mode]' \
     '--fullscreen[start in fullscreen mode]' \
     '--login-shell[start shell as a login shell]' \
diff --git a/config.c b/config.c
index b33f5818..d73e8ec1 100644
--- a/config.c
+++ b/config.c
@@ -209,6 +209,11 @@ parse_section_main(const char *key, const char *value, struct config *conf,
         conf->login_shell = str_to_bool(value);
     }
 
+    else if (strcmp(key, "app-id") == 0) {
+        free(conf->app_id);
+        conf->app_id = strdup(value);
+    }
+
     else if (strcmp(key, "geometry") == 0) {
         unsigned width, height;
         if (sscanf(value, "%ux%u", &width, &height) != 2 || width == 0 || height == 0) {
@@ -827,6 +832,7 @@ config_load(struct config *conf, const char *conf_path)
     *conf = (struct config) {
         .term = strdup("foot"),
         .shell = get_shell(),
+        .app_id = strdup("foot"),
         .width = 700,
         .height = 500,
         .pad_x = 2,
@@ -960,6 +966,7 @@ config_free(struct config conf)
 {
     free(conf.term);
     free(conf.shell);
+    free(conf.app_id);
     tll_free_and_free(conf.fonts, free);
     free(conf.server_socket_path);
 
diff --git a/config.h b/config.h
index 32e381eb..355468fc 100644
--- a/config.h
+++ b/config.h
@@ -10,6 +10,7 @@
 struct config {
     char *term;
     char *shell;
+    char *app_id;
     bool login_shell;
     unsigned width;
     unsigned height;
diff --git a/doc/foot.1.scd b/doc/foot.1.scd
index ccc0bd3c..7207d1c7 100644
--- a/doc/foot.1.scd
+++ b/doc/foot.1.scd
@@ -34,7 +34,11 @@ execute (instead of the shell).
 	Set initial window width and height. Default: *700x500*.
 
 *-t*,*--term*=_TERM_
-	Value to set the environment variable *TERM* to. Default: *foot*.
+	Value to set the environment variable *TERM* to. Default: _foot_.
+
+*-a*,*--app-id*=_ID_
+	Value to set the *app-id* property on the Wayland window
+	to. Default: _foot_.
 
 *--maximized*
 	Start in maximized mode. If both *--maximized* and *--fullscreen*
diff --git a/doc/foot.5.scd b/doc/foot.5.scd
index b354a291..9a977da7 100644
--- a/doc/foot.5.scd
+++ b/doc/foot.5.scd
@@ -56,6 +56,11 @@ in this order:
 *term*
 	Value to set the environment variable *TERM* to. Default: _foot_.
 
+*app-id*
+	Value to set the *app-id* property on the Wayland window to. The
+	compositor can use this value to e.g. group multiple windows, or
+	apply window management rules. Default: _foot_.
+
 *scrollback*
 	Number of scrollback lines. Default: _1000_.
 
diff --git a/doc/footclient.1.scd b/doc/footclient.1.scd
index a4de1089..c7b07466 100644
--- a/doc/footclient.1.scd
+++ b/doc/footclient.1.scd
@@ -13,7 +13,11 @@ execute (instead of the shell).
 # OPTIONS
 
 *-t*,*--term*=_TERM_
-	Value to set the environment variable _TERM_ to. Default: _foot_.
+	Value to set the environment variable *TERM* to. Default: _foot_.
+
+*-a*,*--app-id*=_ID_
+	Value to set the *app-id* property on the Wayland window
+	to. Default: _foot_.
 
 *--maximized*
 	Start in maximized mode. If both *--maximized* and *--fullscreen*
diff --git a/main.c b/main.c
index 06497cbe..add743d1 100644
--- a/main.c
+++ b/main.c
@@ -46,6 +46,7 @@ print_usage(const char *prog_name)
         "  -c,--config=PATH                      load configuration from PATH (XDG_CONFIG_HOME/footrc)\n"
         "  -f,--font=FONT                        comma separated list of fonts in fontconfig format (monospace)\n"
         "  -t,--term=TERM                        value to set the environment variable TERM to (foot)\n"
+        "  -a,--app-id=ID                        window application ID (foot)\n"
         "     --maximized                        start in maximized mode\n"
         "     --fullscreen                       start in fullscreen mode\n"
         "     --login-shell                      start shell as a login shell\n"
@@ -139,6 +140,7 @@ main(int argc, char *const *argv)
     static const struct option longopts[] =  {
         {"config",               required_argument, NULL, 'c'},
         {"term",                 required_argument, NULL, 't'},
+        {"app-id",               required_argument, NULL, 'a'},
         {"login-shell",          no_argument,       NULL, 'L'},
         {"font",                 required_argument, NULL, 'f'},
         {"geometry",             required_argument, NULL, 'g'},
@@ -157,6 +159,7 @@ main(int argc, char *const *argv)
 
     const char *conf_path = NULL;
     const char *conf_term = NULL;
+    const char *conf_app_id = NULL;
     bool login_shell = false;
     tll(char *) conf_fonts = tll_init();
     int conf_width = -1;
@@ -173,7 +176,7 @@ main(int argc, char *const *argv)
     bool log_syslog = true;
 
     while (true) {
-        int c = getopt_long(argc, argv, "c:t:Lf:g:s::Pp:l::Svh", longopts, NULL);
+        int c = getopt_long(argc, argv, "c:t:a:Lf:g:s::Pp:l::Svh", longopts, NULL);
         if (c == -1)
             break;
 
@@ -190,6 +193,10 @@ main(int argc, char *const *argv)
             login_shell = true;
             break;
 
+        case 'a':
+            conf_app_id = optarg;
+            break;
+
         case 'f':
             tll_free_and_free(conf_fonts, free);
             for (char *font = strtok(optarg, ","); font != NULL; font = strtok(NULL, ",")) {
@@ -306,6 +313,10 @@ main(int argc, char *const *argv)
         free(conf.term);
         conf.term = strdup(conf_term);
     }
+    if (conf_app_id != NULL) {
+        free(conf.app_id);
+        conf.app_id = strdup(conf_app_id);
+    }
     if (login_shell)
         conf.login_shell = true;
     if (tll_length(conf_fonts) > 0) {
diff --git a/server.c b/server.c
index 42116f27..37c17477 100644
--- a/server.c
+++ b/server.c
@@ -74,6 +74,7 @@ client_destroy(struct client *client)
     /* TODO: clone server conf completely, so that we can just call
      * conf_destroy() here */
     free(client->conf.term);
+    free(client->conf.app_id);
 
     free(client);
 }
@@ -224,6 +225,19 @@ fdm_client(struct fdm *fdm, int fd, int events, void *data)
         goto shutdown;
     }
 
+    CHECK_BUF(sizeof(uint16_t));
+    uint16_t app_id_len = *(uint16_t *)p; p += sizeof(app_id_len);
+
+    CHECK_BUF(app_id_len);
+    const char *app_id = (const char *)p; p += app_id_len;
+    LOG_DBG("app-id = %.*s", app_id_len, app_id);
+
+    if (app_id_len != strlen(app_id) + 1) {
+        LOG_ERR("app-id length mismatch: indicated = %hu, actual = %zu",
+                app_id_len - 1, strlen(app_id));
+        goto shutdown;
+    }
+
     CHECK_BUF(sizeof(uint8_t));
     const uint8_t maximized = *(const uint8_t *)p; p += sizeof(maximized);
 
@@ -259,6 +273,8 @@ fdm_client(struct fdm *fdm, int fd, int events, void *data)
     client->conf = *server->conf;
     client->conf.term = strlen(term_env) > 0
         ? strdup(term_env) : strdup(server->conf->term);
+    client->conf.app_id = strlen(app_id) > 0
+        ? strdup(app_id) : strdup(server->conf->app_id);
     client->conf.login_shell = login_shell;
 
     if (maximized)
diff --git a/wayland.c b/wayland.c
index 4a553cc6..06c02313 100644
--- a/wayland.c
+++ b/wayland.c
@@ -993,7 +993,7 @@ struct wl_window *
 wayl_win_init(struct terminal *term)
 {
     struct wayland *wayl = term->wl;
-    const struct config *conf = wayl->conf;
+    const struct config *conf = term->conf;
 
     struct wl_window *win = calloc(1, sizeof(*win));
     win->term = term;
@@ -1025,7 +1025,7 @@ wayl_win_init(struct terminal *term)
     win->xdg_toplevel = xdg_surface_get_toplevel(win->xdg_surface);
     xdg_toplevel_add_listener(win->xdg_toplevel, &xdg_toplevel_listener, win);
 
-    xdg_toplevel_set_app_id(win->xdg_toplevel, "foot");
+    xdg_toplevel_set_app_id(win->xdg_toplevel, conf->app_id);
 
     /* Request server-side decorations */
     if (wayl->xdg_decoration_manager != NULL) {