diff --git a/tests/test_preview.py b/tests/test_preview.py
index c8d6525a0..ffa52e5dd 100644
--- a/tests/test_preview.py
+++ b/tests/test_preview.py
@@ -24,7 +24,7 @@ class PreviewTestCase(unittest.TestCase):
 
     def test_long_summarize(self):
         example_paras = [
-            """Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:
+            u"""Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:
             Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in
             Troms county, Norway. The administrative centre of the municipality is
             the city of Tromsø. Outside of Norway, Tromso and Tromsö are
@@ -32,7 +32,7 @@ class PreviewTestCase(unittest.TestCase):
             city in the world with a population above 50,000. The most populous town
             north of it is Alta, Norway, with a population of 14,272 (2013).""",
 
-            """Tromsø lies in Northern Norway. The municipality has a population of
+            u"""Tromsø lies in Northern Norway. The municipality has a population of
             (2015) 72,066, but with an annual influx of students it has over 75,000
             most of the year. It is the largest urban area in Northern Norway and the
             third largest north of the Arctic Circle (following Murmansk and Norilsk).
@@ -46,7 +46,7 @@ class PreviewTestCase(unittest.TestCase):
             in Europe. The city is warmer than most other places located on the same
             latitude, due to the warming effect of the Gulf Stream.""",
 
-            """The city centre of Tromsø contains the highest number of old wooden
+            u"""The city centre of Tromsø contains the highest number of old wooden
             houses in Northern Norway, the oldest house dating from 1789. The Arctic
             Cathedral, a modern church from 1965, is probably the most famous landmark
             in Tromsø. The city is a cultural centre for its region, with several
@@ -60,90 +60,90 @@ class PreviewTestCase(unittest.TestCase):
 
         self.assertEquals(
             desc,
-            "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
-            " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
-            " Troms county, Norway. The administrative centre of the municipality is"
-            " the city of Tromsø. Outside of Norway, Tromso and Tromsö are"
-            " alternative spellings of the city.Tromsø is considered the northernmost"
-            " city in the world with a population above 50,000. The most populous town"
-            " north of it is Alta, Norway, with a population of 14,272 (2013)."
+            u"Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
+            u" Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
+            u" Troms county, Norway. The administrative centre of the municipality is"
+            u" the city of Tromsø. Outside of Norway, Tromso and Tromsö are"
+            u" alternative spellings of the city.Tromsø is considered the northernmost"
+            u" city in the world with a population above 50,000. The most populous town"
+            u" north of it is Alta, Norway, with a population of 14,272 (2013)."
         )
 
         desc = summarize_paragraphs(example_paras[1:], min_size=200, max_size=500)
 
         self.assertEquals(
             desc,
-            "Tromsø lies in Northern Norway. The municipality has a population of"
-            " (2015) 72,066, but with an annual influx of students it has over 75,000"
-            " most of the year. It is the largest urban area in Northern Norway and the"
-            " third largest north of the Arctic Circle (following Murmansk and Norilsk)."
-            " Most of Tromsø, including the city centre, is located on the island of"
-            " Tromsøya, 350 kilometres (217 mi) north of the Arctic Circle. In 2012,"
-            " Tromsøya had a population of 36,088. Substantial parts of the…"
+            u"Tromsø lies in Northern Norway. The municipality has a population of"
+            u" (2015) 72,066, but with an annual influx of students it has over 75,000"
+            u" most of the year. It is the largest urban area in Northern Norway and the"
+            u" third largest north of the Arctic Circle (following Murmansk and Norilsk)."
+            u" Most of Tromsø, including the city centre, is located on the island of"
+            u" Tromsøya, 350 kilometres (217 mi) north of the Arctic Circle. In 2012,"
+            u" Tromsøya had a population of 36,088. Substantial parts of the urban…"
         )
 
     def test_short_summarize(self):
         example_paras = [
-            "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
-            " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
-            " Troms county, Norway.",
+            u"Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
+            u" Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
+            u" Troms county, Norway.",
 
-            "Tromsø lies in Northern Norway. The municipality has a population of"
-            " (2015) 72,066, but with an annual influx of students it has over 75,000"
-            " most of the year.",
+            u"Tromsø lies in Northern Norway. The municipality has a population of"
+            u" (2015) 72,066, but with an annual influx of students it has over 75,000"
+            u" most of the year.",
 
-            "The city centre of Tromsø contains the highest number of old wooden"
-            " houses in Northern Norway, the oldest house dating from 1789. The Arctic"
-            " Cathedral, a modern church from 1965, is probably the most famous landmark"
-            " in Tromsø.",
+            u"The city centre of Tromsø contains the highest number of old wooden"
+            u" houses in Northern Norway, the oldest house dating from 1789. The Arctic"
+            u" Cathedral, a modern church from 1965, is probably the most famous landmark"
+            u" in Tromsø.",
         ]
 
         desc = summarize_paragraphs(example_paras, min_size=200, max_size=500)
 
         self.assertEquals(
             desc,
-            "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
-            " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
-            " Troms county, Norway.\n"
-            "\n"
-            "Tromsø lies in Northern Norway. The municipality has a population of"
-            " (2015) 72,066, but with an annual influx of students it has over 75,000"
-            " most of the year."
+            u"Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
+            u" Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
+            u" Troms county, Norway.\n"
+            u"\n"
+            u"Tromsø lies in Northern Norway. The municipality has a population of"
+            u" (2015) 72,066, but with an annual influx of students it has over 75,000"
+            u" most of the year."
         )
 
     def test_small_then_large_summarize(self):
         example_paras = [
-            "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
-            " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
-            " Troms county, Norway.",
+            u"Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
+            u" Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
+            u" Troms county, Norway.",
 
-            "Tromsø lies in Northern Norway. The municipality has a population of"
-            " (2015) 72,066, but with an annual influx of students it has over 75,000"
-            " most of the year."
-            " The city centre of Tromsø contains the highest number of old wooden"
-            " houses in Northern Norway, the oldest house dating from 1789. The Arctic"
-            " Cathedral, a modern church from 1965, is probably the most famous landmark"
-            " in Tromsø.",
+            u"Tromsø lies in Northern Norway. The municipality has a population of"
+            u" (2015) 72,066, but with an annual influx of students it has over 75,000"
+            u" most of the year."
+            u" The city centre of Tromsø contains the highest number of old wooden"
+            u" houses in Northern Norway, the oldest house dating from 1789. The Arctic"
+            u" Cathedral, a modern church from 1965, is probably the most famous landmark"
+            u" in Tromsø.",
         ]
 
         desc = summarize_paragraphs(example_paras, min_size=200, max_size=500)
         self.assertEquals(
             desc,
-            "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
-            " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
-            " Troms county, Norway.\n"
-            "\n"
-            "Tromsø lies in Northern Norway. The municipality has a population of"
-            " (2015) 72,066, but with an annual influx of students it has over 75,000"
-            " most of the year. The city centre of Tromsø contains the highest number"
-            " of old wooden houses in Northern Norway, the oldest house dating from"
-            " 1789. The Arctic Cathedral, a modern church…"
+            u"Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:"
+            u" Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in"
+            u" Troms county, Norway.\n"
+            u"\n"
+            u"Tromsø lies in Northern Norway. The municipality has a population of"
+            u" (2015) 72,066, but with an annual influx of students it has over 75,000"
+            u" most of the year. The city centre of Tromsø contains the highest number"
+            u" of old wooden houses in Northern Norway, the oldest house dating from"
+            u" 1789. The Arctic Cathedral, a modern church from…"
         )
 
 
 class PreviewUrlTestCase(unittest.TestCase):
     def test_simple(self):
-        html = """
+        html = u"""
         <html>
         <head><title>Foo</title></head>
         <body>
@@ -155,12 +155,12 @@ class PreviewUrlTestCase(unittest.TestCase):
         og = decode_and_calc_og(html, "http://example.com/test.html")
 
         self.assertEquals(og, {
-            "og:title": "Foo",
-            "og:description": "Some text."
+            u"og:title": u"Foo",
+            u"og:description": u"Some text."
         })
 
     def test_comment(self):
-        html = """
+        html = u"""
         <html>
         <head><title>Foo</title></head>
         <body>
@@ -173,12 +173,12 @@ class PreviewUrlTestCase(unittest.TestCase):
         og = decode_and_calc_og(html, "http://example.com/test.html")
 
         self.assertEquals(og, {
-            "og:title": "Foo",
-            "og:description": "Some text."
+            u"og:title": u"Foo",
+            u"og:description": u"Some text."
         })
 
     def test_comment2(self):
-        html = """
+        html = u"""
         <html>
         <head><title>Foo</title></head>
         <body>
@@ -194,12 +194,12 @@ class PreviewUrlTestCase(unittest.TestCase):
         og = decode_and_calc_og(html, "http://example.com/test.html")
 
         self.assertEquals(og, {
-            "og:title": "Foo",
-            "og:description": "Some text.\n\nSome more text.\n\nText\n\nMore text"
+            u"og:title": u"Foo",
+            u"og:description": u"Some text.\n\nSome more text.\n\nText\n\nMore text"
         })
 
     def test_script(self):
-        html = """
+        html = u"""
         <html>
         <head><title>Foo</title></head>
         <body>
@@ -212,6 +212,6 @@ class PreviewUrlTestCase(unittest.TestCase):
         og = decode_and_calc_og(html, "http://example.com/test.html")
 
         self.assertEquals(og, {
-            "og:title": "Foo",
-            "og:description": "Some text."
+            u"og:title": u"Foo",
+            u"og:description": u"Some text."
         })