diff --git a/sao/src/common.js b/sao/src/common.js
index 0ba193fce1..41c84c40ec 100644
--- a/sao/src/common.js
+++ b/sao/src/common.js
@@ -822,9 +822,9 @@
                 var context = field.get_context(record);
                 var jdomain = JSON.stringify([domain, context]);
                 if (jdomain in this._domain_cache) {
-                    let selection = this._domain_cache[jdomain];
+                    let [selection, help] = this._domain_cache[jdomain];
                     if (callback) {
-                        callback(selection, {});
+                        callback(selection, help);
                     }
                     return;
                 }
@@ -852,7 +852,7 @@
                             help[x.id] = x[help_field];
                         }
                     }
-                    this._domain_cache[jdomain] = selection;
+                    this._domain_cache[jdomain] = [selection, help];
 
                     let cur_domain = field.get_domain(record);
                     let cur_context = field.get_context(record);
diff --git a/tryton/tryton/common/selection.py b/tryton/tryton/common/selection.py
index 68d1aae298..3c49ca2612 100644
--- a/tryton/tryton/common/selection.py
+++ b/tryton/tryton/common/selection.py
@@ -62,7 +62,8 @@ class SelectionMixin(object):
             context = field.get_context(record)
             domain_cache_key = (freeze_value(domain), freeze_value(context))
             if domain_cache_key in self._domain_cache:
-                self.selection = self._domain_cache[domain_cache_key]
+                self.selection, self.help = (
+                    self._domain_cache[domain_cache_key])
                 self._last_domain = (domain, context)
             if (domain, context) == self._last_domain:
                 return
@@ -85,7 +86,7 @@ class SelectionMixin(object):
                 else:
                     help_ = {}
                 self._last_domain = (domain, context)
-                self._domain_cache[domain_cache_key] = selection
+                self._domain_cache[domain_cache_key] = (selection, help_)
             else:
                 selection = []
                 if self.nullable_widget: