diff --git a/tmt/base.py b/tmt/base.py
index eca98497c6..e3acc8d33c 100644
--- a/tmt/base.py
+++ b/tmt/base.py
@@ -2341,7 +2341,7 @@ def import_plan(self) -> Optional['Plan']:
         self._imported_plan._original_plan = self
 
         # Update imported plan environment with the local environment
-        self._imported_plan.environment.update(self.environment)
+        self._imported_plan._environment.update(self.environment)
         with tmt.utils.modify_environ(self.environment):
             self._expand_node_data(node.data, {
                 key: ','.join(value)