diff --git a/IPython/core/tests/test_pylabtools.py b/IPython/core/tests/test_pylabtools.py
index a80ed96..16ced0f 100644
--- a/IPython/core/tests/test_pylabtools.py
+++ b/IPython/core/tests/test_pylabtools.py
@@ -51,7 +51,7 @@ def test_figure_to_svg():
     ax.plot([1,2,3])
     plt.draw()
     svg = pt.print_figure(fig, 'svg')[:100].lower()
-    nt.assert_in('doctype svg', svg)
+    nt.assert_in(b'doctype svg', svg)
 
 
 def test_import_pylab():
diff --git a/IPython/nbconvert/filters/citation.py b/IPython/nbconvert/filters/citation.py
index a057420..1442d55 100644
--- a/IPython/nbconvert/filters/citation.py
+++ b/IPython/nbconvert/filters/citation.py
@@ -39,7 +39,7 @@ def citation2latex(s):
 
     tree = html.fragment_fromstring(s, create_parent='div')
     _process_node_cite(tree)
-    s = html.tostring(tree)
+    s = html.tostring(tree, encoding='unicode')
     if s.endswith('</div>'):
         s = s[:-6]
     if s.startswith('<div>'):