diff --git a/Cargo.lock b/Cargo.lock
index bc8becc0..ec8eefbf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1608,6 +1608,7 @@ dependencies = [
  "once_cell",
  "pango",
  "pangocairo",
+ "regex",
  "rust-embed",
  "serde",
  "serde_json",
diff --git a/Cargo.toml b/Cargo.toml
index 4515c4b9..5d948431 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,6 +20,7 @@ libc = "0.2"
 once_cell = "1.4"
 pango = "0.14.0"
 pangocairo = "0.14.0"
+regex = "1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 log = "0.4.0"
diff --git a/src/keyboard.rs b/src/keyboard.rs
index a96e8000..9b83b68d 100644
--- a/src/keyboard.rs
+++ b/src/keyboard.rs
@@ -264,7 +264,7 @@ impl Keyboard {
         }
     }
 
-    fn layout(&self) -> &Layout {
+    pub fn layout(&self) -> &Layout {
         &self.inner().board.layout()
     }
 
diff --git a/src/picker/mod.rs b/src/picker/mod.rs
index d651edeb..4ff673c7 100644
--- a/src/picker/mod.rs
+++ b/src/picker/mod.rs
@@ -4,7 +4,11 @@ use glib::clone;
 use gtk::prelude::*;
 use gtk::subclass::prelude::*;
 use once_cell::sync::Lazy;
-use std::{cell::RefCell, collections::HashMap};
+use regex::Regex;
+use std::{
+    cell::{Cell, RefCell},
+    collections::HashMap,
+};
 
 use crate::Keyboard;
 use backend::DerefCell;
@@ -28,10 +32,23 @@ pub static SCANCODE_LABELS: Lazy<HashMap<String, String>> = Lazy::new(|| {
     labels
 });
 
+fn parse_mod_tap(name: &str) -> Option<(&str, &str)> {
+    let mt_re = Regex::new("MT\\(([^()]+), ([^()]+)\\)").unwrap();
+    mt_re.captures(name).map(|captures| {
+        let mod_name = captures.get(1).unwrap().as_str();
+        let kc_name = captures.get(2).unwrap().as_str();
+        (mod_name, kc_name)
+    })
+}
+
 #[derive(Default)]
 pub struct PickerInner {
     group_box: DerefCell<PickerGroupBox>,
     keyboard: RefCell<Option<Keyboard>>,
+    mod_tap_box: DerefCell<gtk::Box>,
+    mod_tap_check: DerefCell<gtk::CheckButton>,
+    mod_tap_mods: DerefCell<gtk::ComboBoxText>,
+    mod_tap_signal_blocked: Cell<bool>,
 }
 
 #[glib::object_subclass]
@@ -52,13 +69,50 @@ impl ObjectImpl for PickerInner {
             }));
         };
 
+        let mod_tap_mods = cascade! {
+            gtk::ComboBoxText::new();
+            ..append(Some("LEFT_CTRL"), "Left Ctrl");
+            ..append(Some("LEFT_SHIFT"), "Left Shift");
+            ..append(Some("LEFT_ALT"), "Left Alt");
+            ..append(Some("LEFT_SUPER"), "Left Super");
+            ..append(Some("RIGHT_CTRL"), "Right Ctrl");
+            ..append(Some("RIGHT_SHIFT"), "Right Shift");
+            ..append(Some("RIGHT_ALT"), "Right Alt");
+            ..append(Some("RIGHT_SUPER"), "Right Super");
+            ..set_active_id(Some("LEFT_CTRL"));
+            ..connect_active_id_notify(clone!(@weak picker => move |_| {
+                picker.mod_tap_updated();
+            }));
+        };
+
+        let mod_tap_check = cascade! {
+            gtk::CheckButton::with_label("Mod-Tap");
+            ..bind_property("active", &mod_tap_mods, "sensitive").flags(glib::BindingFlags::SYNC_CREATE).build();
+            ..connect_toggled(clone!(@weak picker => move |_| {
+                picker.update_key_visibility();
+                picker.mod_tap_updated();
+            }));
+        };
+
+        let mod_tap_box = cascade! {
+            gtk::Box::new(gtk::Orientation::Horizontal, 8);
+            ..add(&mod_tap_check);
+            ..add(&mod_tap_mods);
+        };
+
         cascade! {
             picker;
+            ..set_spacing(18);
+            ..set_orientation(gtk::Orientation::Vertical);
             ..add(&group_box);
+            ..add(&mod_tap_box);
             ..show_all();
         };
 
         self.group_box.set(group_box);
+        self.mod_tap_box.set(mod_tap_box);
+        self.mod_tap_check.set(mod_tap_check);
+        self.mod_tap_mods.set(mod_tap_mods);
     }
 }
 
@@ -82,42 +136,91 @@ impl Picker {
         PickerInner::from_instance(self)
     }
 
+    fn update_key_visibility(&self) {
+        let kb = match self.keyboard() {
+            Some(kb) => kb,
+            None => return,
+        };
+        let is_mod_tap =
+            self.inner().mod_tap_box.get_visible() && self.inner().mod_tap_check.is_active();
+        self.inner().group_box.set_key_visibility(|name| {
+            // Check that scancode is available for the keyboard
+            let visible = kb.has_scancode(name);
+            let sensitive = !is_mod_tap || kb.layout().scancode_from_name(name).unwrap_or(0) < 256;
+            (visible, sensitive)
+        });
+    }
+
     pub(crate) fn set_keyboard(&self, keyboard: Option<Keyboard>) {
         if let Some(old_kb) = &*self.inner().keyboard.borrow() {
             old_kb.set_picker(None);
         }
 
         if let Some(kb) = &keyboard {
-            // Check that scancode is available for the keyboard
-            self.inner().group_box.set_key_visibility(|name| {
-                let visible = kb.has_scancode(name);
-                let sensitive = true;
-                (visible, sensitive)
-            });
             kb.set_picker(Some(&self));
+
+            self.inner()
+                .mod_tap_box
+                .set_visible(kb.layout().meta.has_mod_tap);
         }
 
         *self.inner().keyboard.borrow_mut() = keyboard;
+        self.update_key_visibility();
     }
 
-    pub(crate) fn set_selected(&self, scancode_names: Vec<String>) {
+    pub(crate) fn set_selected(&self, mut scancode_names: Vec<String>) {
+        self.inner().mod_tap_signal_blocked.set(true);
+
+        self.inner().mod_tap_box.set_sensitive(false);
+        self.inner().mod_tap_check.set_active(false);
+        self.inner().mod_tap_mods.set_active_id(Some("LEFT_CTRL"));
+
+        if scancode_names.len() == 1 {
+            self.inner().mod_tap_box.set_sensitive(true);
+            if let Some((mod_name, _)) = parse_mod_tap(&scancode_names[0]) {
+                self.inner().mod_tap_check.set_active(true);
+                self.inner().mod_tap_mods.set_active_id(Some(mod_name));
+            }
+        }
+
+        self.inner().mod_tap_signal_blocked.set(false);
+
+        for i in scancode_names.iter_mut() {
+            if let Some((_, kc_name)) = parse_mod_tap(&i) {
+                *i = kc_name.to_string();
+            }
+        }
+
         self.inner().group_box.set_selected(scancode_names);
     }
 
-    fn key_pressed(&self, name: String) {
-        let kb = match self.inner().keyboard.borrow().clone() {
+    fn mod_(&self) -> Option<String> {
+        if self.inner().mod_tap_box.get_visible() && self.inner().mod_tap_check.is_active() {
+            Some(self.inner().mod_tap_mods.active_id()?.into())
+        } else {
+            None
+        }
+    }
+
+    fn keyboard(&self) -> Option<Keyboard> {
+        self.inner().keyboard.borrow().clone()
+    }
+
+    fn key_pressed(&self, mut name: String) {
+        let kb = match self.keyboard() {
             Some(kb) => kb,
-            None => {
-                return;
-            }
+            None => return,
         };
         let layer = kb.layer();
 
+        if let Some(mod_) = self.mod_() {
+            name = format!("MT({}, {})", mod_, name);
+        }
+
         info!("Clicked {} layer {:?}", name, layer);
         if let Some(layer) = layer {
             let futures = FuturesUnordered::new();
-            for i in kb.selected().iter() {
-                let i = *i;
+            for i in kb.selected().iter().copied() {
                 futures.push(clone!(@strong kb, @strong name => async move {
                     kb.keymap_set(i, layer, &name).await;
                 }));
@@ -125,6 +228,42 @@ impl Picker {
             glib::MainContext::default().spawn_local(async { futures.collect::<()>().await });
         }
     }
+
+    fn mod_tap_updated(&self) {
+        if self.inner().mod_tap_signal_blocked.get() {
+            return;
+        }
+
+        let kb = match self.keyboard() {
+            Some(kb) => kb,
+            None => return,
+        };
+        let layer = kb.layer();
+
+        if let Some(layer) = layer {
+            let futures = FuturesUnordered::new();
+            for i in kb.selected().iter().copied() {
+                if let Some((_, scancode)) = &kb.board().keys()[i].get_scancode(layer) {
+                    let kc_name = if let Some((_, kc_name)) = parse_mod_tap(scancode) {
+                        kc_name
+                    } else {
+                        scancode
+                    };
+
+                    let name = if let Some(mod_name) = self.mod_() {
+                        format!("MT({}, {})", mod_name, kc_name)
+                    } else {
+                        kc_name.to_string()
+                    };
+
+                    futures.push(clone!(@strong kb, @strong name => async move {
+                        kb.keymap_set(i, layer, &name).await;
+                    }));
+                }
+            }
+            glib::MainContext::default().spawn_local(async { futures.collect::<()>().await });
+        }
+    }
 }
 
 #[cfg(test)]