diff --git a/frontend/document/koptinterface.lua b/frontend/document/koptinterface.lua
index 940921dba..d4e115d9a 100644
--- a/frontend/document/koptinterface.lua
+++ b/frontend/document/koptinterface.lua
@@ -75,7 +75,14 @@ function KoptInterface:createContext(doc, pageno, bbox)
 	kc:setDefectSize(doc.configurable.defect_size)
 	kc:setLineSpacing(doc.configurable.line_spacing)
 	kc:setWordSpacing(doc.configurable.word_spacing)
-	if bbox then kc:setBBox(bbox.x0, bbox.y0, bbox.x1, bbox.y1) end
+	if bbox then
+		if bbox.x0 >= bbox.x1 or bbox.y0 >= bbox.y1 then
+			local page_size = Document.getNativePageDimensions(doc, pageno)
+			bbox.x0, bbox.y0 = 0, 0
+			bbox.x1, bbox.y1 = page_size.w, page_size.h
+		end
+		kc:setBBox(bbox.x0, bbox.y0, bbox.x1, bbox.y1)
+	end
 	if DEBUG.is_on then kc:setDebug() end
 	return kc
 end
diff --git a/frontend/ui/reader/readerhighlight.lua b/frontend/ui/reader/readerhighlight.lua
index 9e3e8f2a3..f7b4dc505 100644
--- a/frontend/ui/reader/readerhighlight.lua
+++ b/frontend/ui/reader/readerhighlight.lua
@@ -212,9 +212,10 @@ function ReaderHighlight:onHold(arg, ges)
 		return true
 	end
 
-	self.selected_word = self.ui.document:getWordFromPosition(self.hold_pos)
-	DEBUG("selected word:", self.selected_word)
-	if self.selected_word then
+	local ok, word = pcall(self.ui.document.getWordFromPosition, self.ui.document, self.hold_pos)
+	if ok and word then
+		DEBUG("selected word:", word)
+		self.selected_word = word
 		if self.ui.document.info.has_pages then
 			local boxes = {}
 			table.insert(boxes, self.selected_word.sbox)
diff --git a/koreader-base b/koreader-base
index f35cbdff9..1bcc96030 160000
--- a/koreader-base
+++ b/koreader-base
@@ -1 +1 @@
-Subproject commit f35cbdff906b265712afffc8831bafe5fbb21f3b
+Subproject commit 1bcc9603034d97cd196c2f3bb2a4a5713d215931