diff --git a/crates/libtiny_tui/src/config.rs b/crates/libtiny_tui/src/config.rs
index c7c26fa6..76d22dc4 100644
--- a/crates/libtiny_tui/src/config.rs
+++ b/crates/libtiny_tui/src/config.rs
@@ -31,6 +31,9 @@ pub(crate) struct Config {
 
     #[serde(default)]
     pub(crate) key_map: Option<KeyMap>,
+
+    #[serde(default)]
+    pub(crate) completion_char: Option<String>,
 }
 
 #[derive(Debug, Deserialize, PartialEq, Eq)]
diff --git a/crates/libtiny_tui/src/input_area/mod.rs b/crates/libtiny_tui/src/input_area/mod.rs
index de8887d5..a33ac8aa 100644
--- a/crates/libtiny_tui/src/input_area/mod.rs
+++ b/crates/libtiny_tui/src/input_area/mod.rs
@@ -52,6 +52,9 @@ pub(crate) struct InputArea {
     /// Current nickname. Not available on initialization (e.g. before registration with the
     /// server). Set with `set_nick`.
     nick: Option<Nickname>,
+
+    // Autocompletion character to be used when at the start of the line. Set with `set_completion_char`.
+    completion_char: Option<String>,
 }
 
 enum Mode {
@@ -120,6 +123,7 @@ impl InputArea {
             history: Vec::with_capacity(HIST_SIZE),
             mode: Mode::Edit,
             nick: None,
+            completion_char: None,
         }
     }
 
@@ -127,6 +131,11 @@ impl InputArea {
         self.nick = Some(Nickname::new(value, color))
     }
 
+    /// Set completion char.
+    pub(crate) fn set_completion_char(&mut self, completion_char: Option<String>) {
+        self.completion_char = completion_char;
+    }
+
     pub(crate) fn get_nick(&self) -> Option<String> {
         self.nick.as_ref().map(|nick| nick.value.clone())
     }
@@ -746,7 +755,17 @@ impl InputArea {
                 }
             };
 
-            dict.drop_pfx(&mut word.iter().cloned())
+            let mut completions = dict.drop_pfx(&mut word.iter().cloned());
+
+            if let Some(completion_suffix) = &self.completion_char {
+                if cursor_left == 0 {
+                    for completion in completions.iter_mut() {
+                        completion.push_str(&format!("{} ", completion_suffix));
+                    }
+                }
+            }
+
+            completions
         };
 
         if !completions.is_empty() {
diff --git a/crates/libtiny_tui/src/messaging.rs b/crates/libtiny_tui/src/messaging.rs
index 159c6e45..55e814ce 100644
--- a/crates/libtiny_tui/src/messaging.rs
+++ b/crates/libtiny_tui/src/messaging.rs
@@ -218,6 +218,10 @@ impl MessagingUI {
         self.input_field.set(str)
     }
 
+    pub(crate) fn set_completion_char(&mut self, completion_char: Option<String>) {
+        self.input_field.set_completion_char(completion_char);
+    }
+
     /// Set cursor location in the input field.
     pub(crate) fn set_cursor(&mut self, cursor: i32) {
         self.input_field.set_cursor(cursor);
diff --git a/crates/libtiny_tui/src/tui.rs b/crates/libtiny_tui/src/tui.rs
index ba950d30..27d8e482 100644
--- a/crates/libtiny_tui/src/tui.rs
+++ b/crates/libtiny_tui/src/tui.rs
@@ -108,6 +108,9 @@ pub struct TUI {
 
     /// TabConfig settings loaded from config file
     tab_configs: TabConfigs,
+
+    // Autocompletion character to be used when at the start of the line.
+    completion_char: Option<String>,
 }
 
 pub(crate) enum CmdResult {
@@ -175,6 +178,7 @@ impl TUI {
             key_map: KeyMap::default(),
             config_path,
             tab_configs: TabConfigs::default(),
+            completion_char: None,
         };
 
         // Init "mentions" tab. This needs to happen right after creating the TUI to be able to
@@ -365,9 +369,11 @@ impl TUI {
                 max_nick_length,
                 key_map,
                 layout,
+                completion_char,
                 ..
             } = config;
             self.set_colors(colors);
+            self.set_completion_char(completion_char);
             self.scrollback = scrollback.max(1);
             self.key_map.load(&key_map.unwrap_or_default());
             if let Some(layout) = layout {
@@ -394,6 +400,14 @@ impl TUI {
         self.colors = colors;
     }
 
+    fn set_completion_char(&mut self, completion_char: Option<String>) {
+        self.completion_char = completion_char;
+        for tab in &mut self.tabs {
+            tab.widget
+                .set_completion_char((&self.completion_char).clone());
+        }
+    }
+
     fn new_tab(&mut self, idx: usize, src: MsgSource, alias: Option<String>) {
         let visible_name = alias.unwrap_or_else(|| match &src {
             MsgSource::Serv { serv } => serv.to_owned(),
diff --git a/crates/tiny/config.yml b/crates/tiny/config.yml
index b5458151..1e0b9e2b 100644
--- a/crates/tiny/config.yml
+++ b/crates/tiny/config.yml
@@ -66,6 +66,10 @@ defaults:
 # Location for chat logs.
 log_dir: "{}"
 
+# Optional character(s) that will be appended at the end of a completed
+# nick, if at the beginning of the line. Uncomment to enable.
+# completion_char: ":"
+
 # Limits the maximum number of messages stored in each tab. Default is
 # unlimited.
 # scrollback: 512