diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 2f37e04a01..147c7970ed 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -792,6 +792,11 @@ class Query(object):
             q_object.add_to_query(self)
             return
 
+        if self.where and q_object.connector != AND and len(q_object) > 1:
+            self.where.start_subtree(AND)
+            subtree = True
+        else:
+            subtree = False
         for child in q_object.children:
             if isinstance(child, Node):
                 self.where.start_subtree(q_object.connector)
@@ -799,6 +804,8 @@ class Query(object):
                 self.where.end_subtree()
             else:
                 self.add_filter(child, q_object.connector, q_object.negated)
+        if subtree:
+            self.where.end_subtree()
 
     def setup_joins(self, names, opts, alias, dupe_multis):
         """
diff --git a/django/utils/tree.py b/django/utils/tree.py
index f7963b1110..b3a0e06812 100644
--- a/django/utils/tree.py
+++ b/django/utils/tree.py
@@ -87,8 +87,8 @@ class Node(object):
     def start_subtree(self, conn_type):
         """
         Sets up internal state so that new nodes are added to a subtree of the
-        current node. The conn_type is required so that the new subtree is
-        connected correctly to any existing nodes in the tree.
+        current node. The conn_type specifies how the sub-tree is joined to the
+        existing children.
         """
         if len(self.children) == 1:
             self.connector = conn_type
diff --git a/tests/regressiontests/queries/models.py b/tests/regressiontests/queries/models.py
index 7c0b83096f..5af1a19e62 100644
--- a/tests/regressiontests/queries/models.py
+++ b/tests/regressiontests/queries/models.py
@@ -459,5 +459,12 @@ order_by() and filter() calls.
 >>> Item.objects.extra(select={'count': 'select count(*) from queries_item_tags where queries_item_tags.item_id = queries_item.id'}).filter(count=1)
 [<Item: four>]
 
+Bug #6154
+Multiple filter statements are joined using "AND" all the time.
+
+>>> Author.objects.filter(id=a1.id).filter(Q(extra__note=n1)|Q(item__note=n3))
+[<Author: a1>]
+>>> Author.objects.filter(Q(extra__note=n1)|Q(item__note=n3)).filter(id=a1.id)
+[<Author: a1>]
 """}