diff --git a/skimage/viewer/canvastools/linetool.py b/skimage/viewer/canvastools/linetool.py
index d777e50b..fed18383 100644
--- a/skimage/viewer/canvastools/linetool.py
+++ b/skimage/viewer/canvastools/linetool.py
@@ -69,7 +69,7 @@ class LineTool(CanvasToolBase):
 
     @property
     def end_points(self):
-        return self._end_pts
+        return self._end_pts.astype(int)
 
     @end_points.setter
     def end_points(self, pts):
diff --git a/skimage/viewer/tests/test_plugins.py b/skimage/viewer/tests/test_plugins.py
index e8c16416..59b1f3e4 100644
--- a/skimage/viewer/tests/test_plugins.py
+++ b/skimage/viewer/tests/test_plugins.py
@@ -32,8 +32,8 @@ def test_line_profile():
                 scan_data.size]:
         assert_equal(inp, 172)
     assert_equal(line_image.shape, (512, 512))
-    assert_allclose(scan_data.max(), 0.9139, rtol=1e-3)
-    assert_allclose(scan_data.mean(), 0.2828, rtol=1e-3)
+    assert_allclose(scan_data.max(), 0.9176, rtol=1e-3)
+    assert_allclose(scan_data.mean(), 0.2812, rtol=1e-3)
 
 
 @skipif(qt_api is None)
@@ -43,12 +43,12 @@ def test_line_profile_rgb():
     for i in range(6):
         plugin.line_tool._thicken_scan_line()
     line_image, scan_data = plugin.output()
-    assert_equal(line_image[line_image == 128].size, 755)
+    assert_equal(line_image[line_image == 128].size, 750)
     assert_equal(line_image[line_image == 255].size, 151)
     assert_equal(line_image.shape, (300, 451))
-    assert_equal(scan_data.shape, (152, 3))
+    assert_equal(scan_data.shape, (151, 3))
     assert_allclose(scan_data.max(), 0.772, rtol=1e-3)
-    assert_allclose(scan_data.mean(), 0.4355, rtol=1e-3)
+    assert_allclose(scan_data.mean(), 0.4359, rtol=1e-3)
 
 
 @skipif(qt_api is None)
@@ -64,7 +64,7 @@ def test_line_profile_dynamic():
     line = lp.get_profiles()[-1][0]
     assert line.size == 129
     assert_almost_equal(np.std(viewer.image), 0.208, 3)
-    assert_almost_equal(np.std(line), 0.226, 3)
+    assert_almost_equal(np.std(line), 0.229, 3)
     assert_almost_equal(np.max(line) - np.min(line), 0.725, 1)
 
     viewer.image = skimage.img_as_float(median(image,
@@ -85,7 +85,7 @@ def test_measure():
 
     m.line_changed([(0, 0), (10, 10)])
     assert_equal(str(m._length.text), '14.1')
-    assert_equal(str(m._angle.text[:5]), u'135.0')
+    assert_equal(str(m._angle.text[:5]), '135.0')
 
 
 @skipif(qt_api is None)
diff --git a/skimage/viewer/tests/test_viewer.py b/skimage/viewer/tests/test_viewer.py
index 00ef848c..75f7413c 100644
--- a/skimage/viewer/tests/test_viewer.py
+++ b/skimage/viewer/tests/test_viewer.py
@@ -2,7 +2,7 @@
 from skimage import data
 from skimage.viewer import ImageViewer, CollectionViewer
 from skimage.transform import pyramid_gaussian
-from skimage.viewer.plugins import OverlayPlugin
+from skimage.viewer.plugins import OverlayPlugin, recent_mpl_version
 from skimage.filter import sobel
 from skimage.viewer.qt import qt_api, QtGui, QtCore
 from numpy.testing import assert_equal
@@ -52,7 +52,7 @@ def test_collection_viewer():
     view._format_coord(10, 10)
 
 
-@skipif(qt_api is None)
+@skipif(qt_api is None or not recent_mpl_version())
 def test_viewer_with_overlay():
     img = data.coins()
     ov = OverlayPlugin(image_filter=sobel)
@@ -74,4 +74,4 @@ def test_viewer_with_overlay():
     assert_equal(ov.filtered_image, img)
 
 
-    
+
diff --git a/skimage/viewer/tests/test_widgets.py b/skimage/viewer/tests/test_widgets.py
index 61450146..54b9b7bb 100644
--- a/skimage/viewer/tests/test_widgets.py
+++ b/skimage/viewer/tests/test_widgets.py
@@ -4,7 +4,6 @@ from skimage import data, img_as_float, io
 from skimage.viewer import ImageViewer
 from skimage.viewer.widgets import (
     Slider, OKCancelButtons, SaveButtons, ComboBox, Text)
-from skimage.viewer.utils import init_qtapp
 from skimage.viewer.plugins.base import Plugin
 
 from skimage.viewer.qt import qt_api, QtGui, QtCore