diff --git a/tests/rules/test_line_length.py b/tests/rules/test_line_length.py
index 7ea2c20..ea7fc2c 100644
--- a/tests/rules/test_line_length.py
+++ b/tests/rules/test_line_length.py
@@ -43,17 +43,17 @@ class LineLengthTestCase(RuleTestCase):
         self.check('---\n', conf)
         self.check(80 * 'a', conf)
         self.check('---\n' + 80 * 'a' + '\n', conf)
-        self.check(81 * 'a', conf, problem=(1, 81))
-        self.check('---\n' + 81 * 'a' + '\n', conf, problem=(2, 81))
-        self.check(1000 * 'b', conf, problem=(1, 81))
-        self.check('---\n' + 1000 * 'b' + '\n', conf, problem=(2, 81))
+        self.check(16 * 'aaaa ' + 'z', conf, problem=(1, 81))
+        self.check('---\n' + 16 * 'aaaa ' + 'z' + '\n', conf, problem=(2, 81))
+        self.check(1000 * 'word ' + 'end', conf, problem=(1, 81))
+        self.check('---\n' + 1000 * 'word ' + 'end\n', conf, problem=(2, 81))
 
     def test_max_length_10(self):
         conf = ('line-length: {max: 10}\n'
                 'new-line-at-end-of-file: disable\n')
-        self.check('---\nABCDEFGHIJ', conf)
-        self.check('---\nABCDEFGHIJK', conf, problem=(2, 11))
-        self.check('---\nABCDEFGHIJK\n', conf, problem=(2, 11))
+        self.check('---\nABCD EFGHI', conf)
+        self.check('---\nABCD EFGHIJ', conf, problem=(2, 11))
+        self.check('---\nABCD EFGHIJ\n', conf, problem=(2, 11))
 
     def test_spaces(self):
         conf = ('line-length: {max: 80}\n'
@@ -61,3 +61,36 @@ class LineLengthTestCase(RuleTestCase):
                 'trailing-spaces: disable\n')
         self.check('---\n' + 81 * ' ', conf, problem=(2, 81))
         self.check('---\n' + 81 * ' ' + '\n', conf, problem=(2, 81))
+
+    def test_non_breakable_word(self):
+        conf = 'line-length: {max: 20, allow-non-breakable-words: yes}'
+        self.check('---\n' + 30 * 'A' + '\n', conf)
+        self.check('---\n'
+                   'this:\n'
+                   '  is:\n'
+                   '    - a:\n'
+                   '        http://localhost/very/long/url\n'
+                   '...\n', conf)
+        self.check('---\n'
+                   'this:\n'
+                   '  is:\n'
+                   '    - a:\n'
+                   '        # http://localhost/very/long/url\n'
+                   '        comment\n'
+                   '...\n', conf)
+
+        conf = 'line-length: {max: 20, allow-non-breakable-words: no}'
+        self.check('---\n' + 30 * 'A' + '\n', conf, problem=(2, 21))
+        self.check('---\n'
+                   'this:\n'
+                   '  is:\n'
+                   '    - a:\n'
+                   '        http://localhost/very/long/url\n'
+                   '...\n', conf, problem=(5, 21))
+        self.check('---\n'
+                   'this:\n'
+                   '  is:\n'
+                   '    - a:\n'
+                   '        # http://localhost/very/long/url\n'
+                   '        comment\n'
+                   '...\n', conf, problem=(5, 21))
diff --git a/yamllint/conf/default.yml b/yamllint/conf/default.yml
index d1d701b..7d72570 100644
--- a/yamllint/conf/default.yml
+++ b/yamllint/conf/default.yml
@@ -35,6 +35,7 @@ rules:
     check-multi-line-strings: no
   line-length:
     max: 80
+    allow-non-breakable-words: yes
   new-line-at-end-of-file: {level: error}
   new-lines:
     type: unix
diff --git a/yamllint/rules/line_length.py b/yamllint/rules/line_length.py
index a3c2cd7..32bed1f 100644
--- a/yamllint/rules/line_length.py
+++ b/yamllint/rules/line_length.py
@@ -20,6 +20,9 @@ Use this rule to set a limit to lines length.
 .. rubric:: Options
 
 * ``max`` defines the maximal (inclusive) length of lines.
+* ``allow-non-breakable-words`` is used to allow non breakable words (without
+  spaces inside) to overflow the limit. This is useful for long URLs, for
+  instance. Use ``yes`` to allow, ``no`` to forbid.
 
 .. rubric:: Examples
 
@@ -38,6 +41,35 @@ Use this rule to set a limit to lines length.
     long sentence:
       Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
       tempor incididunt ut labore et dolore magna aliqua.
+
+#. With ``line-length: {max: 60, allow-non-breakable-words: yes}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    this:
+      is:
+        - a:
+            http://localhost/very/very/very/very/very/very/very/very/long/url
+
+    # this comment is too long,
+    # but hard to split:
+    # http://localhost/another/very/very/very/very/very/very/very/very/long/url
+
+   the following code snippet would **FAIL**:
+   ::
+
+    - this line is waaaaaaaaaaaaaay too long but could be easily splitted...
+
+#. With ``line-length: {max: 60, allow-non-breakable-words: no}``
+
+   the following code snippet would **FAIL**:
+   ::
+
+    this:
+      is:
+        - a:
+            http://localhost/very/very/very/very/very/very/very/very/long/url
 """
 
 
@@ -46,11 +78,24 @@ from yamllint.linter import LintProblem
 
 ID = 'line-length'
 TYPE = 'line'
-CONF = {'max': int}
+CONF = {'max': int,
+        'allow-non-breakable-words': bool}
 
 
 def check(conf, line):
     if line.end - line.start > conf['max']:
+        if conf['allow-non-breakable-words']:
+            start = line.start
+            while start < line.end and line.buffer[start] == ' ':
+                start += 1
+
+            if start != line.end:
+                if line.buffer[start] == '#':
+                    start += 2
+
+                if line.buffer.find(' ', start, line.end) == -1:
+                    return
+
         yield LintProblem(line.line_no, conf['max'] + 1,
                           'line too long (%d > %d characters)' %
                           (line.end - line.start, conf['max']))