diff --git a/.gitignore b/.gitignore
index cbf117ff..9aae7811 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.pyc
 *.pyo
 *.so
+*.swp
 __pycache__
 .coverage
 .coverage.*
diff --git a/CHANGES.rst b/CHANGES.rst
index 400dd846..a988b410 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,8 +5,11 @@
 5.1.2 (unreleased)
 ==================
 
-- Nothing changed yet.
-
+- Make sure to call each invariant only once when validating invariants.
+  Previously, invariants could be called multiple times because when an
+  invariant is defined in an interface, it's found by in all interfaces
+  inheriting from that interface.  See `pull request 215
+  <https://github.com/zopefoundation/zope.interface/pull/215/>`_.
 
 5.1.1 (2020-09-30)
 ==================
@@ -45,7 +48,6 @@
      Note that such potential errors are not new, they are just once
      again a possibility.
 
-
 5.1.0 (2020-04-08)
 ==================
 
diff --git a/src/zope/interface/interface.py b/src/zope/interface/interface.py
index f819441d..d100aae2 100644
--- a/src/zope/interface/interface.py
+++ b/src/zope/interface/interface.py
@@ -877,19 +877,17 @@ def queryDescriptionFor(self, name, default=None):
 
     def validateInvariants(self, obj, errors=None):
         """validate object to defined invariants."""
-        for call in self.queryTaggedValue('invariants', []):
-            try:
-                call(obj)
-            except Invalid as e:
-                if errors is None:
-                    raise
-                errors.append(e)
-        for base in self.__bases__:
-            try:
-                base.validateInvariants(obj, errors)
-            except Invalid:
-                if errors is None:
-                    raise
+
+        for iface in self.__iro__:
+            for invariant in iface.queryDirectTaggedValue('invariants', ()):
+                try:
+                    invariant(obj)
+                except Invalid as error:
+                     if errors is not None:
+                         errors.append(error)
+                     else:
+                         raise
+
         if errors:
             raise Invalid(errors)
 
diff --git a/src/zope/interface/tests/test_interface.py b/src/zope/interface/tests/test_interface.py
index 036e8582..9dc2aff6 100644
--- a/src/zope/interface/tests/test_interface.py
+++ b/src/zope/interface/tests/test_interface.py
@@ -1014,6 +1014,20 @@ def _fail(*args, **kw):
         self.assertEqual(len(_errors), 1)
         self.assertTrue(isinstance(_errors[0], Invalid))
 
+    def test_validateInvariants_inherited_not_called_multiple_times(self):
+        _passable_called_with = []
+
+        def _passable(*args, **kw):
+            _passable_called_with.append((args, kw))
+            return True
+
+        obj = object()
+        base = self._makeOne('IBase')
+        base.setTaggedValue('invariants', [_passable])
+        derived = self._makeOne('IDerived', (base,))
+        derived.validateInvariants(obj)
+        self.assertEqual(1, len(_passable_called_with))
+
     def test___reduce__(self):
         iface = self._makeOne('PickleMe')
         self.assertEqual(iface.__reduce__(), 'PickleMe')