diff --git a/src/Row.cpp b/src/Row.cpp
index ad492c1a7a..3fb87bd7e1 100644
--- a/src/Row.cpp
+++ b/src/Row.cpp
@@ -203,8 +203,8 @@ void Row::setSelectionAndMargins(DocIterator const & beg,
 	setSelection(beg.pos(), end.pos());
 
 	if (selection()) {
-		end_margin_sel = isMarginSelected(false, beg, end);
-		begin_margin_sel = isMarginSelected(true, beg, end);
+		change(end_margin_sel, isMarginSelected(false, beg, end));
+		change(begin_margin_sel, isMarginSelected(true, beg, end));
 	}
 }
 
@@ -212,18 +212,18 @@ void Row::setSelectionAndMargins(DocIterator const & beg,
 void Row::setSelection(pos_type beg, pos_type end) const
 {
 	if (pos_ >= beg && pos_ <= end)
-		sel_beg = pos_;
+		change(sel_beg, pos_);
 	else if (beg > pos_ && beg <= end_)
-		sel_beg = beg;
+		change(sel_beg, beg);
 	else
-		sel_beg = -1;
+		change(sel_beg, -1);
 
 	if (end_ >= beg && end_ <= end)
-		sel_end = end_;
+		change(sel_end,end_);
 	else if (end < end_ && end >= pos_)
-		sel_end = end;
+		change(sel_end, end);
 	else
-		sel_end = -1;
+		change(sel_end, -1);
 }
 
 
diff --git a/src/Row.h b/src/Row.h
index a1fedd7e5d..49513d32b9 100644
--- a/src/Row.h
+++ b/src/Row.h
@@ -136,6 +136,29 @@ public:
 
 	///
 	Row();
+	/**
+	 * Helper function: set variable \c var to value \c val, and mark
+	 * row as changed is the values were different. This is intended
+	 * for use when changing members of the row object.
+	 */
+	template<class T1, class T2>
+	void change(T1 & var, T2 const val) {
+		if (var != val)
+			changed(true);
+		var = val;
+	}
+	/**
+	 * Helper function: set variable \c var to value \c val, and mark
+	 * row as changed is the values were different. This is intended
+	 * for use when changing members of the row object.
+	 * This is the const version, useful for mutable members.
+	 */
+	template<class T1, class T2>
+	void change(T1 & var, T2 const val) const {
+		if (var != val)
+			changed(true);
+		var = val;
+	}
 	///
 	bool changed() const { return changed_; }
 	///
diff --git a/src/TextMetrics.cpp b/src/TextMetrics.cpp
index 42637d7899..e7bd6190e2 100644
--- a/src/TextMetrics.cpp
+++ b/src/TextMetrics.cpp
@@ -1884,9 +1884,9 @@ void TextMetrics::drawParagraph(PainterInfo & pi, pit_type const pit, int const
 		// whether this row is the first or last and update the margins.
 		if (row.selection()) {
 			if (row.sel_beg == 0)
-				row.begin_margin_sel = sel_beg.pit() < pit;
+				row.change(row.begin_margin_sel, sel_beg.pit() < pit);
 			if (row.sel_end == sel_end_par.lastpos())
-				row.end_margin_sel = sel_end.pit() > pit;
+				row.change(row.end_margin_sel, sel_end.pit() > pit);
 		}
 
 		// has row changed since last paint?