diff --git a/CHANGELOG b/CHANGELOG
index fd5066e8de..0ac3237dce 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Add clear_all method to Cache
 * Support Genshi element directives in HTML editor
 * Add firstline tool
 * Add support for Python 3.9
diff --git a/doc/ref/cache.rst b/doc/ref/cache.rst
index b4da3cb700..12bd659b7f 100644
--- a/doc/ref/cache.rst
+++ b/doc/ref/cache.rst
@@ -35,6 +35,10 @@ Sets the ``value`` of the ``key`` in the cache.
 
 Clears all the keys in the cache.
 
+.. classmethod:: clear_all()
+
+Clears all cache instances.
+
 .. classmethod:: sync(transaction)
 
 Synchronize cache instances using transaction.
diff --git a/trytond/cache.py b/trytond/cache.py
index 489454fd88..96107a97fd 100644
--- a/trytond/cache.py
+++ b/trytond/cache.py
@@ -75,6 +75,11 @@ class BaseCache(object):
     def clear(self):
         raise NotImplementedError
 
+    @classmethod
+    def clear_all(cls):
+        for inst in cls._instances.values():
+            inst.clear()
+
     @classmethod
     def sync(cls, transaction):
         raise NotImplementedError
diff --git a/trytond/modules/__init__.py b/trytond/modules/__init__.py
index 2493a6fc3c..6fad3d12d5 100644
--- a/trytond/modules/__init__.py
+++ b/trytond/modules/__init__.py
@@ -299,6 +299,9 @@ def load_module_graph(graph, pool, update=None, lang=None):
         while modules_todo:
             (module, to_delete) = modules_todo.pop()
             convert.post_import(pool, module, to_delete)
+
+        # Ensure cache is clear for other instances
+        Cache.clear_all()
     logger.info('all modules loaded')