diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index d4e1e9630..ec48f67a5 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -2058,9 +2058,18 @@ expanded to last):
 
 | `+${re:N}+` |
   Regex captured group: `0` = whole string matching, `1` to `99` = group
-  captured, `+++` = last group captured. |
-  `+${re:1}+` |
-  `+test+`
+  captured, `+++` = last group captured,
+  `#` = index of last group captured (_WeeChat ≥ 1.8_). |
+  `+${re:0}+` +
+  `+${re:1}+` +
+  `+${re:2}+` +
+  `+${re:+++}+` +
+  `+${re:#}+` |
+  `+test1 test2+` +
+  `+test1+` +
+  `+test2+` +
+  `+test2+` +
+  `+2+`
 
 | `+${color:name}+` |
   WeeChat color code (the name of color has optional attributes),
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index a2fea8a0d..4b1761935 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -2101,9 +2101,18 @@ première étendue à la dernière) :
 
 | `+${re:N}+` |
   Groupe regex capturé : `0` = toute la chaîne correspondante,
-  `1` à `99` = groupe capturé, `+++` = dernier groupe capturé. |
-  `+${re:1}+` |
-  `+test+`
+  `1` à `99` = groupe capturé, `+++` = dernier groupe capturé,
+  `#` = index du dernier groupe capturé (_WeeChat ≥ 1.8_). |
+  `+${re:0}+` +
+  `+${re:1}+` +
+  `+${re:2}+` +
+  `+${re:+++}+` +
+  `+${re:#}+` |
+  `+test1 test2+` +
+  `+test1+` +
+  `+test2+` +
+  `+test2+` +
+  `+2+`
 
 | `+${color:nom}+` |
   Code couleur WeeChat (le nom de couleur a des attributs facultatifs),
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index 31e610f08..8f70f1402 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -2136,9 +2136,18 @@ expanded to last):
 
 | `+${re:N}+` |
   Regex captured group: `0` = whole string matching, `1` to `99` = group
-  captured, `+++` = last group captured. |
-  `+${re:1}+` |
-  `+test+`
+  captured, `+++` = last group captured,
+  `#` = index of last group captured (_WeeChat ≥ 1.8_). |
+  `+${re:0}+` +
+  `+${re:1}+` +
+  `+${re:2}+` +
+  `+${re:+++}+` +
+  `+${re:#}+` |
+  `+test1 test2+` +
+  `+test1+` +
+  `+test2+` +
+  `+test2+` +
+  `+2+`
 
 | `+${color:name}+` |
   WeeChat color code (the name of color has optional attributes),
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index 12e89b394..feee8826f 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -2064,11 +2064,21 @@ char *weechat_string_eval_expression (const char *expr,
   `+this…+` +
   `+こ>>+`
 
+// TRANSLATION MISSING
 | `+${re:N}+` |
   正規表現のキャプチャグループ: `0` = マッチするすべての文字列、`1` から `99` =
-  キャプチャされたグループ、`+++` = 最後にキャプチャされたグループ |
-  `+${re:1}+` |
-  `+test+`
+  キャプチャされたグループ、`+++` = 最後にキャプチャされたグループ、
+  `#` = index of last group captured (_WeeChat ≥ 1.8_). |
+  `+${re:0}+` +
+  `+${re:1}+` +
+  `+${re:2}+` +
+  `+${re:+++}+` +
+  `+${re:#}+` |
+  `+test1 test2+` +
+  `+test1+` +
+  `+test2+` +
+  `+test2+` +
+  `+2+`
 
 | `+${color:name}+` |
   WeeChat 色コード (色名部分はオプション属性をとることも可能です),
diff --git a/src/core/wee-eval.c b/src/core/wee-eval.c
index 62dc6981b..016d99c2d 100644
--- a/src/core/wee-eval.c
+++ b/src/core/wee-eval.c
@@ -464,6 +464,12 @@ eval_replace_vars_cb (void *data, const char *text)
         {
             if (strcmp (text + 3, "+") == 0)
                 number = eval_regex->last_match;
+            else if (strcmp (text + 3, "#") == 0)
+            {
+                snprintf (str_value, sizeof (str_value),
+                          "%d", eval_regex->last_match);
+                return strdup (str_value);
+            }
             else
             {
                 number = strtol (text + 3, &error, 10);
diff --git a/tests/unit/core/test-eval.cpp b/tests/unit/core/test-eval.cpp
index 4f2a92e8e..e0bd236b7 100644
--- a/tests/unit/core/test-eval.cpp
+++ b/tests/unit/core/test-eval.cpp
@@ -402,6 +402,13 @@ TEST(Eval, EvalReplaceRegex)
                    "password=abc password=def");
     regfree (&regex);
 
+    /* regex groups */
+    hashtable_remove (pointers, "regex");
+    hashtable_set (options, "regex", "([a-z]+) ([a-z]+) ([a-z]+) ([a-z]+)");
+    hashtable_set (options, "regex_replace",
+                   "${re:0} -- ${re:1} ${re:+} (${re:#})");
+    WEE_CHECK_EVAL("abc def ghi jkl -- abc jkl (4)", "abc def ghi jkl");
+
     hashtable_free (pointers);
     hashtable_free (extra_vars);
     hashtable_free (options);