diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index 8105d5261b..04ec31b035 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -3039,4 +3039,45 @@ void Buffer::updateLabels(ParIterator & parit) const
 	}
 }
 
+
+bool Buffer::nextWord(DocIterator & from, DocIterator & to,
+	docstring & word) const
+{
+	bool inword = false;
+	bool ignoreword = false;
+	string lang_code;
+	to = from;
+
+	while (to.depth()) {
+		if (isLetter(to)) {
+			if (!inword) {
+				inword = true;
+				ignoreword = false;
+				from = to;
+				word.clear();
+				lang_code = to.paragraph().getFontSettings(params(),
+					to.pos()).language()->code();
+			}
+			// Insets like optional hyphens and ligature
+			// break are part of a word.
+			if (!to.paragraph().isInset(to.pos())) {
+				char_type const c = to.paragraph().getChar(to.pos());
+				word += c;
+				if (isDigit(c))
+					ignoreword = true;
+			}
+		} else { // !isLetter(cur)
+			if (inword)
+				if (!word.empty() && !ignoreword) {
+					return true;
+				}
+				inword = false;
+		}
+
+		to.forwardPos();
+	}
+
+	return false;
+}
+
 } // namespace lyx
diff --git a/src/Buffer.h b/src/Buffer.h
index 6b983177cd..5d7b0d94e2 100644
--- a/src/Buffer.h
+++ b/src/Buffer.h
@@ -492,6 +492,15 @@ public:
 	///
 	void updateLabels(ParIterator & parit) const;
 
+	/// Find next word starting from \p from.
+	/// \p from initial position to search, will then points to the next
+	///    word.
+	/// \p to will points to the end of the next word.
+	/// \p word will contain the found word if any.
+	/// \return true if a new word was found.
+	bool nextWord(DocIterator & from, DocIterator & to,
+		docstring & word) const;
+
 private:
 	/// search for macro in local (buffer) table or in children
 	MacroData const * getBufferMacro(docstring const & name,
diff --git a/src/DocIterator.cpp b/src/DocIterator.cpp
index 40c4ae4adc..51433d4781 100644
--- a/src/DocIterator.cpp
+++ b/src/DocIterator.cpp
@@ -17,6 +17,7 @@
 #include "Buffer.h"
 #include "InsetList.h"
 #include "Paragraph.h"
+#include "LyXRC.h"
 #include "Text.h"
 
 #include "mathed/MathData.h"
@@ -27,10 +28,12 @@
 
 #include "support/debug.h"
 #include "support/lassert.h"
+#include "support/lstrings.h"
 
 #include <ostream>
 
 using namespace std;
+using namespace lyx::support;
 
 namespace lyx {
 
@@ -607,4 +610,16 @@ bool operator==(StableDocIterator const & dit1, StableDocIterator const & dit2)
 }
 
 
+bool isLetter(DocIterator const & dit)
+{
+	return dit.inTexted()
+		&& dit.inset().allowSpellCheck()
+		&& dit.pos() != dit.lastpos()
+		&& (dit.paragraph().isLetter(dit.pos())
+		    // We want to pass the ' and escape chars to ispell
+		    || contains(from_utf8(lyxrc.spellchecker_esc_chars + '\''),
+				dit.paragraph().getChar(dit.pos())))
+		&& !dit.paragraph().isDeleted(dit.pos());
+}
+
 } // namespace lyx
diff --git a/src/DocIterator.h b/src/DocIterator.h
index 737cbd3b13..14baf2566f 100644
--- a/src/DocIterator.h
+++ b/src/DocIterator.h
@@ -355,6 +355,9 @@ private:
 	std::vector<CursorSlice> data_;
 };
 
+/// Indicate if the character pointed by dit is a letter.
+/// This function takes care of spellchecker escape chars.
+bool isLetter(DocIterator const & dit);
 
 } // namespace lyx
 
diff --git a/src/frontends/qt4/GuiSpellchecker.cpp b/src/frontends/qt4/GuiSpellchecker.cpp
index ee53817314..41aa782bab 100644
--- a/src/frontends/qt4/GuiSpellchecker.cpp
+++ b/src/frontends/qt4/GuiSpellchecker.cpp
@@ -241,59 +241,23 @@ void GuiSpellchecker::clearParams()
 }
 
 
-static bool isLetter(DocIterator const & dit)
-{
-	return dit.inTexted()
-		&& dit.inset().allowSpellCheck()
-		&& dit.pos() != dit.lastpos()
-		&& (dit.paragraph().isLetter(dit.pos())
-		    // We want to pass the ' and escape chars to ispell
-		    || contains(from_utf8(lyxrc.spellchecker_esc_chars + '\''),
-				dit.paragraph().getChar(dit.pos())))
-		&& !dit.paragraph().isDeleted(dit.pos());
-}
-
-
 static WordLangTuple nextWord(Cursor & cur, ptrdiff_t & progress)
 {
-	BufferParams const & bp = cur.bv().buffer().params();
-	bool inword = false;
-	bool ignoreword = false;
+	Buffer const & buf = cur.bv().buffer();
 	cur.resetAnchor();
 	docstring word;
-	string lang_code;
+	DocIterator from = cur;
+	DocIterator to;
+	if (!buf.nextWord(from, to, word))
+		return WordLangTuple(docstring(), string());
 
-	while (cur.depth()) {
-		if (isLetter(cur)) {
-			if (!inword) {
-				inword = true;
-				ignoreword = false;
-				cur.resetAnchor();
-				word.clear();
-				lang_code = cur.paragraph().getFontSettings(bp, cur.pos()).language()->code();
-			}
-			// Insets like optional hyphens and ligature
-			// break are part of a word.
-			if (!cur.paragraph().isInset(cur.pos())) {
-				char_type const c = cur.paragraph().getChar(cur.pos());
-				word += c;
-				if (isDigit(c))
-					ignoreword = true;
-			}
-		} else { // !isLetter(cur)
-			if (inword)
-				if (!word.empty() && !ignoreword) {
-					cur.setSelection();
-					return WordLangTuple(word, lang_code);
-				}
-				inword = false;
-		}
-
-		cur.forwardPos();
-		++progress;
-	}
-
-	return WordLangTuple(docstring(), string());
+	cur.setCursor(from);
+	cur.resetAnchor();
+	cur.setCursor(to);
+	cur.setSelection();
+	string lang_code = from.paragraph().getFontSettings(buf.params(), cur.pos()).language()->code();
+	++progress;
+	return WordLangTuple(word, lang_code);
 }