diff --git a/weboob/applications/pastoob/pastoob.py b/weboob/applications/pastoob/pastoob.py
index 81c266d2..3b0b9c18 100644
--- a/weboob/applications/pastoob/pastoob.py
+++ b/weboob/applications/pastoob/pastoob.py
@@ -91,7 +91,7 @@ class Pastoob(ReplApplication):
         params = self._get_params()
         backends = {}
         for backend in self.weboob.iter_backends():
-            score = backend.can_post(**params)
+            score = backend.can_post(contents, **params)
             if score:
                 backends.setdefault(score, []).append(backend)
         # select a random backend from the best scores
diff --git a/weboob/backends/pastealacon/backend.py b/weboob/backends/pastealacon/backend.py
index 57a79ce0..a8d08549 100644
--- a/weboob/backends/pastealacon/backend.py
+++ b/weboob/backends/pastealacon/backend.py
@@ -49,7 +49,11 @@ class PastealaconBackend(BaseBackend, BasePasteBackend):
     def new_paste(self, *args, **kwargs):
         return PastealaconPaste(*args, **kwargs)
 
-    def can_post(self, public=None, max_age=None):
+    def can_post(self, contents, public=None, max_age=None):
+        try:
+            contents.encode(self.browser.ENCODING)
+        except UnicodeEncodeError:
+            return 0
         if public is False:
             return 0
         if max_age is not None:
diff --git a/weboob/backends/pastealacon/test.py b/weboob/backends/pastealacon/test.py
index cd6e190c..e49109ec 100644
--- a/weboob/backends/pastealacon/test.py
+++ b/weboob/backends/pastealacon/test.py
@@ -81,11 +81,13 @@ class PastealaconTest(BackendTest):
         assert self.backend.get_paste('nJG9ZFG8') is None
 
     def test_can_post(self):
-        assert 0 == self.backend.can_post(public=False)
-        assert 1 == self.backend.can_post(public=True)
-        assert 0 == self.backend.can_post(public=True, max_age=600)
-        assert 1 == self.backend.can_post(public=True, max_age=3600*24)
-        assert 1 == self.backend.can_post(public=True, max_age=3600*24*3)
-        assert 1 == self.backend.can_post(public=True, max_age=False)
-        assert 1 == self.backend.can_post(public=None, max_age=False)
-        assert 1 == self.backend.can_post(public=True, max_age=3600*24*40)
+        assert 0 == self.backend.can_post('hello', public=False)
+        assert 1 == self.backend.can_post('hello', public=True)
+        assert 0 == self.backend.can_post('hello', public=True, max_age=600)
+        assert 1 == self.backend.can_post('hello', public=True, max_age=3600*24)
+        assert 1 == self.backend.can_post('hello', public=True, max_age=3600*24*3)
+        assert 1 == self.backend.can_post('hello', public=True, max_age=False)
+        assert 1 == self.backend.can_post('hello', public=None, max_age=False)
+        assert 1 == self.backend.can_post('hello', public=True, max_age=3600*24*40)
+        assert 1 == self.backend.can_post(u'héhé', public=True)
+        assert 0 == self.backend.can_post(u'hello ♥', public=True)
diff --git a/weboob/backends/pastebin/backend.py b/weboob/backends/pastebin/backend.py
index ce71f4f3..2917a916 100644
--- a/weboob/backends/pastebin/backend.py
+++ b/weboob/backends/pastebin/backend.py
@@ -63,7 +63,7 @@ class PastebinBackend(BaseBackend, BasePasteBackend):
     def new_paste(self, *args, **kwargs):
         return PastebinPaste(*args, **kwargs)
 
-    def can_post(self, public=None, max_age=None):
+    def can_post(self, contents, public=None, max_age=None):
         if max_age is not None:
             if self.get_closest_expiration(max_age) is None:
                 return 0
diff --git a/weboob/backends/pastebin/test.py b/weboob/backends/pastebin/test.py
index 365fddf2..484d6969 100644
--- a/weboob/backends/pastebin/test.py
+++ b/weboob/backends/pastebin/test.py
@@ -79,12 +79,14 @@ class PastebinTest(BackendTest):
         assert self.backend.get_paste('http://pastealacon.com/1') is None
 
     def test_can_post(self):
-        assert self.backend.can_post(public=None) > 0
-        assert self.backend.can_post(public=True) > 0
-        assert self.backend.can_post(public=False) > 0
-        assert self.backend.can_post(public=True, max_age=600) > 0
-        assert self.backend.can_post(public=True, max_age=3600*24) > 0
-        assert self.backend.can_post(public=True, max_age=3600*24*3) > 0
-        assert self.backend.can_post(public=True, max_age=False) > 0
-        assert self.backend.can_post(public=None, max_age=False) > 0
-        assert self.backend.can_post(public=True, max_age=3600*24*40) > 0
+        assert self.backend.can_post('hello', public=None) > 0
+        assert self.backend.can_post('hello', public=True) > 0
+        assert self.backend.can_post('hello', public=False) > 0
+        assert self.backend.can_post('hello', public=True, max_age=600) > 0
+        assert self.backend.can_post('hello', public=True, max_age=3600*24) > 0
+        assert self.backend.can_post('hello', public=True, max_age=3600*24*3) > 0
+        assert self.backend.can_post('hello', public=True, max_age=False) > 0
+        assert self.backend.can_post('hello', public=None, max_age=False) > 0
+        assert self.backend.can_post('hello', public=True, max_age=3600*24*40) > 0
+        assert self.backend.can_post(u'héhé', public=True) > 0
+        assert self.backend.can_post(u'hello ♥', public=True) > 0
diff --git a/weboob/capabilities/paste.py b/weboob/capabilities/paste.py
index 2ce31f12..e3aba399 100644
--- a/weboob/capabilities/paste.py
+++ b/weboob/capabilities/paste.py
@@ -64,13 +64,15 @@ class ICapPaste(IBaseCap):
         """
         raise NotImplementedError()
 
-    def can_post(self, public=None, max_age=None):
+    def can_post(self, contents, public=None, max_age=None):
         """
         Checks if the paste can be pasted by this backend.
         Some properties are considered required (public/private, max_age) while others
         are just bonuses (language).
 
-        public: True must be public, False must be private, None do not care
+        contents: Can be used to check encodability, maximum length, etc.
+        public: True must be public, False must be private, None do not care.
+        max_age: Maximum time to live in seconds.
 
         A score of 0 means the backend is not suitable.
         A score of 1 means the backend is suitable.