diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index 1739c129..ac2436ad 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -594,7 +594,7 @@ class Script(object):
                 self._evaluator.eval_statement(stmt)
 
         analysis = [a for a in self._evaluator.analysis if self.path == a.path]
-        return sorted(analysis, key=lambda x: x.line)
+        return sorted(set(analysis), key=lambda x: x.line)
 
 
 class Interpreter(Script):
diff --git a/jedi/evaluate/analysis.py b/jedi/evaluate/analysis.py
index 42dd674e..965c892e 100644
--- a/jedi/evaluate/analysis.py
+++ b/jedi/evaluate/analysis.py
@@ -37,6 +37,16 @@ class Error(object):
     def __str__(self):
         return '%s: %s:%s' % (self.code, self.line, self.description())
 
+    def __eq__(self, other):
+        return (self.path == other.path and self.name == other.name
+                and self._start_pos == other._start_pos)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __hash__(self):
+        return hash((self.path, self._start_pos, self.name))
+
     def __repr__(self):
         return '<%s %s: %s@%s,%s' % (self.__class__.__name__,
                                      self.name, self.path,