diff --git a/common/action.c b/common/action.c
index ecd5a7e9..f7ae85b9 100644
--- a/common/action.c
+++ b/common/action.c
@@ -100,40 +100,29 @@ void process_action(keyrecord_t *record)
                                                                     action.key.mods<<4;
                 switch (action.layer_tap.code) {
     #ifndef NO_ACTION_ONESHOT
-                    case 0x00:
+                    case MODS_ONESHOT:
                         // Oneshot modifier
                         if (event.pressed) {
                             if (tap_count == 0) {
-                                dprint("MODS_TAP: Oneshot: add_mods\n");
                                 register_mods(mods);
                             }
                             else if (tap_count == 1) {
                                 dprint("MODS_TAP: Oneshot: start\n");
                                 set_oneshot_mods(mods);
                             }
-                            else if (tap_count == TAPPING_TOGGLE) {
-                                dprint("MODS_TAP: Oneshot: toggle\n");
-                                oneshot_toggle();
-                            }
                             else {
-                                dprint("MODS_TAP: Oneshot: cancel&add_mods\n");
-                                // double tap cancels oneshot and works as normal modifier.
-                                clear_oneshot_mods();
                                 register_mods(mods);
                             }
                         } else {
                             if (tap_count == 0) {
-                                dprint("MODS_TAP: Oneshot: cancel/del_mods\n");
-                                // cancel oneshot on hold
                                 clear_oneshot_mods();
                                 unregister_mods(mods);
                             }
                             else if (tap_count == 1) {
-                                // Oneshot
+                                // Retain Oneshot mods
                             }
                             else {
-                                dprint("MODS_TAP: Oneshot: del_mods\n");
-                                // cancel Mods
+                                clear_oneshot_mods();
                                 unregister_mods(mods);
                             }
                         }
diff --git a/common/action_util.c b/common/action_util.c
index 50d686a0..99a3adaa 100644
--- a/common/action_util.c
+++ b/common/action_util.c
@@ -18,6 +18,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "report.h"
 #include "debug.h"
 #include "action_util.h"
+#include "timer.h"
 
 static inline void add_key_byte(uint8_t code);
 static inline void del_key_byte(uint8_t code);
@@ -35,17 +36,28 @@ static uint8_t weak_mods = 0;
 report_keyboard_t *keyboard_report = &(report_keyboard_t){};
 
 #ifndef NO_ACTION_ONESHOT
-static bool oneshot_enabled = true;
 static int8_t oneshot_mods = 0;
+#if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
+static int16_t oneshot_time = 0;
 #endif
+#endif
+
 
 void send_keyboard_report(void) {
     keyboard_report->mods  = real_mods;
     keyboard_report->mods |= weak_mods;
 #ifndef NO_ACTION_ONESHOT
-    keyboard_report->mods |= oneshot_mods;
-    if (has_anykey()) {
-        clear_oneshot_mods();
+    if (oneshot_mods) {
+#if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
+        if (TIMER_DIFF_16(timer_read(), oneshot_time) >= ONESHOT_TIMEOUT) {
+            dprintf("Oneshot: timeout\n");
+            clear_oneshot_mods();
+        }
+#endif
+        keyboard_report->mods |= oneshot_mods;
+        if (has_anykey()) {
+            clear_oneshot_mods();
+        }
     }
 #endif
     host_keyboard_send(keyboard_report);
@@ -99,11 +111,20 @@ void clear_weak_mods(void) { weak_mods = 0; }
 
 /* Oneshot modifier */
 #ifndef NO_ACTION_ONESHOT
-void set_oneshot_mods(uint8_t mods) { oneshot_mods = mods; }
-void clear_oneshot_mods(void) { oneshot_mods = 0; }
-void oneshot_toggle(void) { oneshot_enabled = !oneshot_enabled; }
-void oneshot_enable(void) { oneshot_enabled = true; }
-void oneshot_disable(void) { oneshot_enabled = false; }
+void set_oneshot_mods(uint8_t mods)
+{
+    oneshot_mods = mods;
+#if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
+    oneshot_time = timer_read();
+#endif
+}
+void clear_oneshot_mods(void)
+{
+    oneshot_mods = 0;
+#if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
+    oneshot_time = 0;
+#endif
+}
 #endif
 
 
diff --git a/doc/keymap.md b/doc/keymap.md
index c509651b..11e80a9c 100644
--- a/doc/keymap.md
+++ b/doc/keymap.md
@@ -516,13 +516,14 @@ This is a feature to assign both toggle layer and momentary switch layer action
     ACTION_LAYER_TAP_TOGGLE(1)
 
 
-### 4.3 One Shot Modifier
-This adds oneshot feature to modifier key. 'One Shot Modifier' is one time modifier which has effect only on following just one key.
-It works as normal modifier key when holding but oneshot modifier when tapping.
+### 4.3 Oneshot Modifier
+This runs onetime effect swhich modify only on just one following key. It works as normal modifier key when holding down while oneshot modifier when tapping.
 
     ACTION_MODS_ONESHOT(MOD_LSFT)
 
-Say you want to type 'The', you have to push and hold Shift before type 't' then release Shift before type 'h' and 'e' or you'll get 'THe'. With One Shot Modifier you can tap Shift then type 't', 'h' and 'e' normally, you don't need to holding Shift key properly here.
+Say you want to type 'The', you have to push and hold Shift key before type 't' then release it before type 'h' and 'e', otherwise you'll get 'THe' or 'the' unintentionally. With Oneshot Modifier you can tap Shift then type 't', 'h' and 'e' normally, you don't need to holding Shift key properly here. This mean you can realease Shift before 't' is pressed down.
+
+Oneshot effect is cancel unless following key is pressed down within `ONESHOT_TIMEOUT` of `config.h`. No timeout when it is `0` or not defined.