diff --git a/src/Core/Settings.h b/src/Core/Settings.h
index 501cd61e70c..d0e2f459e8e 100644
--- a/src/Core/Settings.h
+++ b/src/Core/Settings.h
@@ -428,7 +428,6 @@ struct Settings : public SettingsCollection<Settings>
     M(SettingUInt64, mark_cache_min_lifetime, 0, "Obsolete setting, does nothing. Will be removed after 2020-05-31", 0) \
     M(SettingBool, partial_merge_join, false, "Obsolete. Use join_algorithm='prefer_partial_merge' instead.", 0) \
     M(SettingUInt64, max_memory_usage_for_all_queries, 0, "Obsolete. Will be removed after 2020-10-20", 0) \
-    M(SettingBool, cast_keep_nullable, false, "Cast operator keep Nullable for new data type", 0) \
     M(SettingBool, data_type_default_nullable, false, "Data types without NULL or NOT NULL will make Nullable", 0) \
 
 
diff --git a/src/Functions/FunctionsConversion.h b/src/Functions/FunctionsConversion.h
index 207e7759683..64708f45598 100644
--- a/src/Functions/FunctionsConversion.h
+++ b/src/Functions/FunctionsConversion.h
@@ -41,7 +41,6 @@
 #include <Functions/DateTimeTransforms.h>
 #include <DataTypes/DataTypeLowCardinality.h>
 #include <Columns/ColumnLowCardinality.h>
-#include <Core/Settings.h>
 
 
 namespace DB
@@ -2407,11 +2406,6 @@ protected:
                 " Instead there is a column with the following structure: " + column->dumpStructure(),
                 ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
 
-        Settings set;
-        if (set.cast_keep_nullable)
-            if (arguments.back().type->isNullable()) {
-                return makeNullable(DataTypeFactory::instance().get(type_col->getValue<String>()));
-            }
         return DataTypeFactory::instance().get(type_col->getValue<String>());
     }