diff --git a/django/contrib/contenttypes/fields.py b/django/contrib/contenttypes/fields.py
index 35df584dbc..4346e01785 100644
--- a/django/contrib/contenttypes/fields.py
+++ b/django/contrib/contenttypes/fields.py
@@ -15,6 +15,7 @@ from django.db.models.fields.related import (
 )
 from django.db.models.query_utils import PathInfo
 from django.db.models.sql import AND
+from django.db.models.sql.where import WhereNode
 from django.utils.functional import cached_property
 
 
@@ -466,11 +467,11 @@ class GenericRelation(ForeignObject):
         return ContentType.objects.get_for_model(self.model,
                                                  for_concrete_model=self.for_concrete_model)
 
-    def get_extra_restriction(self, where_class, alias, remote_alias):
+    def get_extra_restriction(self, alias, remote_alias):
         field = self.remote_field.model._meta.get_field(self.content_type_field_name)
         contenttype_pk = self.get_content_type().pk
         lookup = field.get_lookup('exact')(field.get_col(remote_alias), contenttype_pk)
-        return where_class([lookup], connector=AND)
+        return WhereNode([lookup], connector=AND)
 
     def bulk_related_objects(self, objs, using=DEFAULT_DB_ALIAS):
         """
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index 8f2a367d65..ac45127fde 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -711,7 +711,7 @@ class ForeignObject(RelatedField):
         """
         return {}
 
-    def get_extra_restriction(self, where_class, alias, related_alias):
+    def get_extra_restriction(self, alias, related_alias):
         """
         Return a pair condition used for joining and subquery pushdown. The
         condition is something that responds to as_sql(compiler, connection)
diff --git a/django/db/models/fields/reverse_related.py b/django/db/models/fields/reverse_related.py
index 12160add7f..ccc2223a5f 100644
--- a/django/db/models/fields/reverse_related.py
+++ b/django/db/models/fields/reverse_related.py
@@ -164,8 +164,8 @@ class ForeignObjectRel(FieldCacheMixin):
     def get_joining_columns(self):
         return self.field.get_reverse_joining_columns()
 
-    def get_extra_restriction(self, where_class, alias, related_alias):
-        return self.field.get_extra_restriction(where_class, related_alias, alias)
+    def get_extra_restriction(self, alias, related_alias):
+        return self.field.get_extra_restriction(related_alias, alias)
 
     def set_field_name(self):
         """
diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 4413b00825..36eee4b2a7 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -1504,7 +1504,6 @@ class SQLDeleteCompiler(SQLCompiler):
             pk.get_col(self.query.get_initial_alias())
         ]
         outerq = Query(self.query.model)
-        outerq.where = self.query.where_class()
         if not self.connection.features.update_can_self_select:
             # Force the materialization of the inner query to allow reference
             # to the target table on MySQL.
@@ -1626,7 +1625,7 @@ class SQLUpdateCompiler(SQLCompiler):
 
         # Now we adjust the current query: reset the where clause and get rid
         # of all the tables we don't need (since they're in the sub-select).
-        self.query.where = self.query.where_class()
+        self.query.clear_where()
         if self.query.related_updates or must_pre_select:
             # Either we're using the idents in multiple update queries (so
             # don't want them to change), or the db backend doesn't support
diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py
index 85278cd8d3..e08b570350 100644
--- a/django/db/models/sql/datastructures.py
+++ b/django/db/models/sql/datastructures.py
@@ -78,8 +78,7 @@ class Join:
 
         # Add a single condition inside parentheses for whatever
         # get_extra_restriction() returns.
-        extra_cond = self.join_field.get_extra_restriction(
-            compiler.query.where_class, self.table_alias, self.parent_alias)
+        extra_cond = self.join_field.get_extra_restriction(self.table_alias, self.parent_alias)
         if extra_cond:
             extra_sql, extra_params = compiler.compile(extra_cond)
             join_conditions.append('(%s)' % extra_sql)
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index af5f684943..8ecac4a3b7 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -144,7 +144,7 @@ class Query(BaseExpression):
 
     compiler = 'SQLCompiler'
 
-    def __init__(self, model, where=WhereNode, alias_cols=True):
+    def __init__(self, model, alias_cols=True):
         self.model = model
         self.alias_refcount = {}
         # alias_map is the most important data structure regarding joins.
@@ -175,8 +175,7 @@ class Query(BaseExpression):
         # clause to contain other than default fields (values(), subqueries...)
         # Note that annotations go to annotations dictionary.
         self.select = ()
-        self.where = where()
-        self.where_class = where
+        self.where = WhereNode()
         # The group_by attribute can have one of the following forms:
         #  - None: no group by at all in the query
         #  - A tuple of expressions: group by (at least) those expressions.
@@ -1265,7 +1264,7 @@ class Query(BaseExpression):
             condition = filter_expr.resolve_expression(self, allow_joins=allow_joins)
             if not isinstance(condition, Lookup):
                 condition = self.build_lookup(['exact'], condition, True)
-            return self.where_class([condition], connector=AND), []
+            return WhereNode([condition], connector=AND), []
         arg, value = filter_expr
         if not arg:
             raise FieldError("Cannot parse keyword query %r" % arg)
@@ -1286,7 +1285,7 @@ class Query(BaseExpression):
 
         if reffed_expression:
             condition = self.build_lookup(lookups, reffed_expression, value)
-            return self.where_class([condition], connector=AND), []
+            return WhereNode([condition], connector=AND), []
 
         opts = self.get_meta()
         alias = self.get_initial_alias()
@@ -1329,7 +1328,7 @@ class Query(BaseExpression):
 
         condition = self.build_lookup(lookups, col, value)
         lookup_type = condition.lookup_name
-        clause = self.where_class([condition], connector=AND)
+        clause = WhereNode([condition], connector=AND)
 
         require_outer = lookup_type == 'isnull' and condition.rhs is True and not current_negated
         if current_negated and (lookup_type != 'isnull' or condition.rhs is False) and condition.rhs is not None:
@@ -1381,6 +1380,9 @@ class Query(BaseExpression):
     def build_where(self, filter_expr):
         return self.build_filter(filter_expr, allow_joins=False)[0]
 
+    def clear_where(self):
+        self.where = WhereNode()
+
     def _add_q(self, q_object, used_aliases, branch_negated=False,
                current_negated=False, allow_joins=True, split_subq=True,
                check_filterable=True):
@@ -1388,8 +1390,7 @@ class Query(BaseExpression):
         connector = q_object.connector
         current_negated = current_negated ^ q_object.negated
         branch_negated = branch_negated or q_object.negated
-        target_clause = self.where_class(connector=connector,
-                                         negated=q_object.negated)
+        target_clause = WhereNode(connector=connector, negated=q_object.negated)
         joinpromoter = JoinPromoter(q_object.connector, len(q_object.children), current_negated)
         for child in q_object.children:
             child_clause, needed_inner = self.build_filter(
@@ -1408,7 +1409,7 @@ class Query(BaseExpression):
         connector = q_object.connector
         current_negated ^= q_object.negated
         branch_negated = branch_negated or q_object.negated
-        target_clause = self.where_class(connector=connector, negated=q_object.negated)
+        target_clause = WhereNode(connector=connector, negated=q_object.negated)
         for child in q_object.children:
             if isinstance(child, Node):
                 child_clause = self.build_filtered_relation_q(
@@ -2301,8 +2302,7 @@ class Query(BaseExpression):
             select_fields = [r[0] for r in join_field.related_fields]
             select_alias = lookup_tables[trimmed_paths + 1]
             self.unref_alias(lookup_tables[trimmed_paths])
-            extra_restriction = join_field.get_extra_restriction(
-                self.where_class, None, lookup_tables[trimmed_paths + 1])
+            extra_restriction = join_field.get_extra_restriction(None, lookup_tables[trimmed_paths + 1])
             if extra_restriction:
                 self.where.add(extra_restriction, AND)
         else:
diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index e83112b046..904f1d096b 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -37,7 +37,7 @@ class DeleteQuery(Query):
         num_deleted = 0
         field = self.get_meta().pk
         for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
-            self.where = self.where_class()
+            self.clear_where()
             self.add_q(Q(
                 **{field.attname + '__in': pk_list[offset:offset + GET_ITERATOR_CHUNK_SIZE]}))
             num_deleted += self.do_query(self.get_meta().db_table, self.where, using=using)
@@ -70,7 +70,7 @@ class UpdateQuery(Query):
     def update_batch(self, pk_list, values, using):
         self.add_update_values(values)
         for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
-            self.where = self.where_class()
+            self.clear_where()
             self.add_q(Q(pk__in=pk_list[offset: offset + GET_ITERATOR_CHUNK_SIZE]))
             self.get_compiler(using).execute_sql(NO_RESULTS)
 
diff --git a/docs/releases/4.0.txt b/docs/releases/4.0.txt
index 244f113c54..9162588d07 100644
--- a/docs/releases/4.0.txt
+++ b/docs/releases/4.0.txt
@@ -504,6 +504,11 @@ Miscellaneous
   individual nodes to a string. ``Node.render()`` should always return a string
   as documented.
 
+* The ``where_class`` property of ``django.db.models.sql.query.Query`` and the
+  ``where_class`` argument to the private ``get_extra_restriction()`` method of
+  ``ForeignObject`` and ``ForeignObjectRel`` are removed. If needed, initialize
+  ``django.db.models.sql.where.WhereNode`` instead.
+
 .. _deprecated-features-4.0:
 
 Features deprecated in 4.0
diff --git a/tests/foreign_object/models/article.py b/tests/foreign_object/models/article.py
index f9fa8bbbd1..a892ce299d 100644
--- a/tests/foreign_object/models/article.py
+++ b/tests/foreign_object/models/article.py
@@ -32,7 +32,7 @@ class ActiveTranslationField(models.ForeignObject):
     """
     requires_unique_target = False
 
-    def get_extra_restriction(self, where_class, alias, related_alias):
+    def get_extra_restriction(self, alias, related_alias):
         return ColConstraint(alias, 'lang', get_language())
 
     def get_extra_descriptor_filter(self, instance):
diff --git a/tests/foreign_object/models/empty_join.py b/tests/foreign_object/models/empty_join.py
index 8ccecc55cb..da151ae8e7 100644
--- a/tests/foreign_object/models/empty_join.py
+++ b/tests/foreign_object/models/empty_join.py
@@ -43,7 +43,7 @@ class StartsWithRelation(models.ForeignObject):
         """
         return self.remote_field
 
-    def get_extra_restriction(self, where_class, alias, related_alias):
+    def get_extra_restriction(self, alias, related_alias):
         to_field = self.remote_field.model._meta.get_field(self.to_fields[0])
         from_field = self.model._meta.get_field(self.from_fields[0])
         return StartsWith(to_field.get_col(alias), from_field.get_col(related_alias))
@@ -87,7 +87,7 @@ class BrokenContainsRelation(StartsWithRelation):
     This model is designed to yield no join conditions and
     raise an exception in ``Join.as_sql()``.
     """
-    def get_extra_restriction(self, where_class, alias, related_alias):
+    def get_extra_restriction(self, alias, related_alias):
         return None