diff --git a/src/libs/solutions/tasking/tasktree.h b/src/libs/solutions/tasking/tasktree.h
index b4119219a1b..647c680b5b0 100644
--- a/src/libs/solutions/tasking/tasktree.h
+++ b/src/libs/solutions/tasking/tasktree.h
@@ -16,7 +16,7 @@ QT_END_NAMESPACE
 
 namespace Tasking {
 
-Q_NAMESPACE
+Q_NAMESPACE_EXPORT(TASKING_EXPORT)
 
 class ExecutionContextActivator;
 class TaskContainer;