diff --git a/defaults.lua b/defaults.lua
index 4e19dd417..1eefe2292 100644
--- a/defaults.lua
+++ b/defaults.lua
@@ -48,6 +48,8 @@ DKOPTREADER_CONFIG_DOC_LANGS_TEXT = {"English", "Chinese_S", "Chinese_T"}
 DKOPTREADER_CONFIG_DOC_LANGS_CODE = {"eng", "chi_sim", "chi_tra"}  -- ISO 639-3 language string, 
 DKOPTREADER_CONFIG_DOC_DEFAULT_LANG_CODE = "eng"  -- and make sure you have corresponding training data 
 
+-- gesture detector defaults
+DGESDETECT_DISABLE_DOUBLE_TAP = true
 
 -- ####################################################################
 -- following features are not supported right now
diff --git a/frontend/ui/gesturedetector.lua b/frontend/ui/gesturedetector.lua
index a84aa5181..2ed90be7d 100644
--- a/frontend/ui/gesturedetector.lua
+++ b/frontend/ui/gesturedetector.lua
@@ -350,7 +350,8 @@ function GestureDetector:handleDoubleTap(tev)
 	DEBUG("set up tap timer")
 	-- deadline should be calculated by adding current tap time and the interval
 	local deadline = cur_tap.timev + TimeVal:new{
-		sec = 0, usec = self.DOUBLE_TAP_INTERVAL,
+		sec = 0,
+		usec = not Input.disable_double_tap and self.DOUBLE_TAP_INTERVAL or 0,
 	}
 	Input:setTimeout(function()
 		DEBUG("in tap timer", self.last_taps[slot] ~= nil)
diff --git a/frontend/ui/inputevent.lua b/frontend/ui/inputevent.lua
index 186a81145..8a28b6ab3 100644
--- a/frontend/ui/inputevent.lua
+++ b/frontend/ui/inputevent.lua
@@ -136,6 +136,7 @@ Input = {
 	},
 	rotation = 0,
 	timer_callbacks = {},
+	disable_double_tap = DGESDETECT_DISABLE_DOUBLE_TAP,
 }
 
 function Input:initKeyMap()
diff --git a/frontend/ui/uimanager.lua b/frontend/ui/uimanager.lua
index edb88423b..a54560616 100644
--- a/frontend/ui/uimanager.lua
+++ b/frontend/ui/uimanager.lua
@@ -56,16 +56,22 @@ function UIManager:show(widget, x, y)
 	self:setDirty(widget)
 	-- tell the widget that it is shown now
 	widget:handleEvent(Event:new("Show"))
+	-- check if this widget disables double tap gesture
+	if widget.disable_double_tap then
+		Input.disable_double_tap = true
+	end
 end
 
 -- unregister a widget
 function UIManager:close(widget)
+	Input.disable_double_tap = DGESDETECT_DISABLE_DOUBLE_TAP
 	local dirty = false
 	for i = #self._window_stack, 1, -1 do
 		if self._window_stack[i].widget == widget then
 			table.remove(self._window_stack, i)
 			dirty = true
-			break
+		elseif self._window_stack[i].widget.disable_double_tap then
+			Input.disable_double_tap = true
 		end
 	end
 	if dirty then
@@ -236,7 +242,7 @@ function UIManager:run()
 				refresh_type = 0
 			end
 			if force_fast_refresh then
-				self.waveform_mode = self.fast_waveform_mode
+				waveform_mode = self.fast_waveform_mode
 			end
 			if self.update_region_func then
 				local update_region = self.update_region_func()
diff --git a/frontend/ui/widget/inputtext.lua b/frontend/ui/widget/inputtext.lua
index 7c347a74b..fe936f476 100644
--- a/frontend/ui/widget/inputtext.lua
+++ b/frontend/ui/widget/inputtext.lua
@@ -102,6 +102,7 @@ function InputText:addChar(char)
 end
 
 function InputText:delChar()
+	if self.charpos == 1 then return end
 	self.charpos = self.charpos - 1
 	table.remove(self.charlist, self.charpos)
 	self.text = self:CharlistToString()
diff --git a/frontend/ui/widget/keyboard.lua b/frontend/ui/widget/keyboard.lua
index 472ca89aa..39cad6e72 100644
--- a/frontend/ui/widget/keyboard.lua
+++ b/frontend/ui/widget/keyboard.lua
@@ -69,12 +69,6 @@ function VirtualKey:init()
 					range = self.dimen,
 				},
 			},
-			DoubleTapSelect = {
-				GestureRange:new{
-					ges = "double_tap",
-					range = self.dimen,
-				},
-			},
 		}
 	end
 end
@@ -88,16 +82,6 @@ function VirtualKey:onTapSelect()
 	return true
 end
 
-function VirtualKey:onDoubleTapSelect()
-	self[1].invert = true
-	if self.callback then
-		self.callback() -- once
-		self.callback() -- twice
-	end
-	UIManager:scheduleIn(0.02, function() self:invert(false) end)
-	return true
-end
-
 function VirtualKey:invert(invert)
 	self[1].invert = invert
 	UIManager.update_region_func = function()
@@ -109,6 +93,7 @@ end
 
 VirtualKeyboard = InputContainer:new{
 	is_always_active = true,
+	disable_double_tap = true,
 	inputbox = nil,
 	KEYS = {}, -- table to store layouts
 	min_layout = 2,
diff --git a/koreader-base b/koreader-base
index 30bf7abc3..214baabb9 160000
--- a/koreader-base
+++ b/koreader-base
@@ -1 +1 @@
-Subproject commit 30bf7abc31f144e6deba1b0ae4dadef9d7ac742e
+Subproject commit 214baabb94680c3b7b17f3168463ac2868279f53