diff --git a/docs/class_reference.md b/docs/class_reference.md
index c992d8e..6eb2353 100644
--- a/docs/class_reference.md
+++ b/docs/class_reference.md
@@ -835,10 +835,10 @@ is equivalent to:
 Returns the whole query as a SQL string.
 
 
-#### conditions_as_sql()
+#### conditions_as_sql(prewhere=True)
 
 
-Returns the contents of the query's `WHERE` clause as a string.
+Returns the contents of the query's `WHERE` or `PREWHERE` clause as a string.
 
 
 #### count()
@@ -943,10 +943,10 @@ This method is not supported on `AggregateQuerySet`.
 Returns the whole query as a SQL string.
 
 
-#### conditions_as_sql()
+#### conditions_as_sql(prewhere=True)
 
 
-Returns the contents of the query's `WHERE` clause as a string.
+Returns the contents of the query's `WHERE` or `PREWHERE` clause as a string.
 
 
 #### count()
diff --git a/docs/querysets.md b/docs/querysets.md
index 965950e..2329000 100644
--- a/docs/querysets.md
+++ b/docs/querysets.md
@@ -17,19 +17,19 @@ The `filter` and `exclude` methods are used for filtering the matching instances
 
     >>> qs = Person.objects_in(database)
     >>> qs = qs.filter(first_name__startswith='V').exclude(birthday__lt='2000-01-01')
-    >>> qs.conditions_as_sql(qs._where)
+    >>> qs.conditions_as_sql()
     u"first_name LIKE 'V%' AND NOT (birthday < '2000-01-01')"
 
 It is possible to specify several fields to filter or exclude by:
 
     >>> qs = Person.objects_in(database).filter(last_name='Smith', height__gt=1.75)
-    >>> qs.conditions_as_sql(qs._where)
+    >>> qs.conditions_as_sql()
     u"last_name = 'Smith' AND height > 1.75"
 
 For filters with compound conditions you can use `Q` objects inside `filter` with overloaded operators `&` (AND), `|` (OR) and `~` (NOT):
 
     >>> qs = Person.objects_in(database).filter((Q(first_name='Ciaran', last_name='Carver') | Q(height_lte=1.8)) & ~Q(first_name='David'))
-    >>> qs.conditions_as_sql(qs._where)
+    >>> qs.conditions_as_sql()
     u"((first_name = 'Ciaran' AND last_name = 'Carver') OR height <= 1.8) AND (NOT (first_name = 'David'))"
 
 By default conditions from `filter` and `exclude` methods are add to `WHERE` clause. 
@@ -37,7 +37,7 @@ For better aggregation performance you can add them to `PREWHERE` section using
 
     >>> qs = Person.objects_in(database)
     >>> qs = qs.filter(first_name__startswith='V', prewhere=True)
-    >>> qs.conditions_as_sql(qs._prewhere)
+    >>> qs.conditions_as_sql(prewhere=True)
     u"first_name LIKE 'V%'"
     
 There are different operators that can be used, by passing `<fieldname>__<operator>=<value>` (two underscores separate the field name from the operator). In case no operator is given, `eq` is used by default. Below are all the supported operators.
diff --git a/docs/ref.md b/docs/ref.md
index a298d04..e750d18 100644
--- a/docs/ref.md
+++ b/docs/ref.md
@@ -482,9 +482,9 @@ infi.clickhouse_orm.query
 #### QuerySet(model_cls, database)
 
 
-#### conditions_as_sql()
+#### conditions_as_sql(prewhere=True)
 
-Return the contents of the queryset's WHERE clause.
+Return the contents of the queryset's WHERE or `PREWHERE` clause.
 
 
 #### count()