diff --git a/src/live_effects/lpe-ruler.cpp b/src/live_effects/lpe-ruler.cpp
index 852592219a..7ba5a7913d 100644
--- a/src/live_effects/lpe-ruler.cpp
+++ b/src/live_effects/lpe-ruler.cpp
@@ -78,9 +78,12 @@ LPERuler::ruler_mark(Geom::Point const &A, Geom::Point const &n, MarkType const
     using namespace Geom;
 
     double real_mark_length = mark_length;
-    real_mark_length = Inkscape::Util::Quantity::convert(real_mark_length, unit.get_abbreviation(), "px");
+    SPDocument * document = SP_ACTIVE_DOCUMENT;
+    SPNamedView *nv = sp_document_namedview(document, NULL);
+    Glib::ustring display_unit = nv->display_units->abbr;
+    real_mark_length = Inkscape::Util::Quantity::convert(real_mark_length, unit.get_abbreviation(), display_unit.c_str());
     double real_minor_mark_length = minor_mark_length;
-    real_minor_mark_length = Inkscape::Util::Quantity::convert(real_minor_mark_length, unit.get_abbreviation(), "px");
+    real_minor_mark_length = Inkscape::Util::Quantity::convert(real_minor_mark_length, unit.get_abbreviation(), display_unit.c_str());
 
     n_major = real_mark_length * n;
     n_minor = real_minor_mark_length * n;
@@ -130,10 +133,13 @@ LPERuler::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_i
     std::vector<double> s_cuts;
 
     double real_mark_distance = mark_distance;
-    real_mark_distance = Inkscape::Util::Quantity::convert(real_mark_distance, unit.get_abbreviation(), "px");
+    SPDocument * document = SP_ACTIVE_DOCUMENT;
+    SPNamedView *nv = sp_document_namedview(document, NULL);
+    Glib::ustring display_unit = nv->display_units->abbr;
+    real_mark_distance = Inkscape::Util::Quantity::convert(real_mark_distance, unit.get_abbreviation(), display_unit.c_str());
 
     double real_offset = offset;
-    real_offset = Inkscape::Util::Quantity::convert(real_offset, unit.get_abbreviation(), "px");
+    real_offset = Inkscape::Util::Quantity::convert(real_offset, unit.get_abbreviation(), display_unit.c_str());
     for (double s = real_offset; s<totlength; s+=real_mark_distance){
         s_cuts.push_back(s);
     }