diff --git a/crud/borders.lua b/crud/borders.lua
index 1a54f9005..6c8a5187d 100644
--- a/crud/borders.lua
+++ b/crud/borders.lua
@@ -16,8 +16,8 @@ local borders = {}
 local STAT_FUNC_NAME = '_crud.get_border_on_storage'
 
 
-local function get_border_on_storage(border_name, space_name, index_id, field_names)
-    dev_checks('string', 'string', 'number', '?table')
+local function get_border_on_storage(border_name, space_name, index_name, field_names)
+    dev_checks('string', 'string', 'string|number', '?table')
 
     assert(border_name == 'min' or border_name == 'max')
 
@@ -26,9 +26,9 @@ local function get_border_on_storage(border_name, space_name, index_id, field_na
         return nil, BorderError:new("Space %q doesn't exist", space_name)
     end
 
-    local index = space.index[index_id]
+    local index = space.index[index_name]
     if index == nil then
-        return nil, BorderError:new("Index %q of space doesn't exist", index_id, space_name)
+        return nil, BorderError:new("Index %q of space doesn't exist", index_name, space_name)
     end
 
     local function get_index_border(index)
@@ -164,7 +164,7 @@ end
 --  A space name
 --
 -- @param ?string index_name
---  An index name (by default, primary index is used)
+--  An index name as well as numerical id (by default, primary index is used)
 --
 -- @tparam ?number opts.timeout
 --  Function call timeout
@@ -175,8 +175,8 @@ end
 -- @return[1] result
 -- @treturn[2] nil
 -- @treturn[2] table Error description
-function borders.min(space_name, index_id, opts)
-    return get_border('min', space_name, index_id, opts)
+function borders.min(space_name, index_name, opts)
+    return get_border('min', space_name, index_name, opts)
 end
 
 --- Find the maximum value in the specified index
@@ -187,7 +187,7 @@ end
 --  A space name
 --
 -- @param ?string index_name
---  An index name (by default, primary index is used)
+--  An index name as well as numerical id (by default, primary index is used)
 --
 -- @tparam ?number opts.timeout
 --  Function call timeout
@@ -198,8 +198,8 @@ end
 -- @return[1] result
 -- @treturn[2] nil
 -- @treturn[2] table Error description
-function borders.max(space_name, index_id, opts)
-    return get_border('max', space_name, index_id, opts)
+function borders.max(space_name, index_name, opts)
+    return get_border('max', space_name, index_name, opts)
 end
 
 return borders
diff --git a/crud/select.lua b/crud/select.lua
index 41964e1fe..093901468 100644
--- a/crud/select.lua
+++ b/crud/select.lua
@@ -35,8 +35,8 @@ function checkers.vshard_call_mode(p)
     return p == 'write' or p == 'read'
 end
 
-local function select_on_storage(space_name, index_id, conditions, opts)
-    dev_checks('string', 'number', '?table', {
+local function select_on_storage(space_name, index_name, conditions, opts)
+    dev_checks('string', 'string|number', '?table', {
         scan_value = 'table',
         after_tuple = '?table',
         tarantool_iter = 'number',
@@ -50,9 +50,9 @@ local function select_on_storage(space_name, index_id, conditions, opts)
         return nil, SelectError:new("Space %q doesn't exist", space_name)
     end
 
-    local index = space.index[index_id]
+    local index = space.index[index_name]
     if index == nil then
-        return nil, SelectError:new("Index with ID %s doesn't exist", index_id)
+        return nil, SelectError:new("Index with ID %s doesn't exist", index_name)
     end
 
     local filter_func, err = select_filters.gen_func(space, conditions, {