diff --git a/src/plugins/projectexplorer/extracompiler.cpp b/src/plugins/projectexplorer/extracompiler.cpp
index 5313275dec3..9fb7cd3ad78 100644
--- a/src/plugins/projectexplorer/extracompiler.cpp
+++ b/src/plugins/projectexplorer/extracompiler.cpp
@@ -160,6 +160,7 @@ void ExtraCompiler::compileImpl(const ContentProvider &provider)
     d->m_taskTree.reset(new TaskTree({taskItemImpl(provider)}));
     connect(d->m_taskTree.get(), &TaskTree::done, this, finalize);
     connect(d->m_taskTree.get(), &TaskTree::errorOccurred, this, finalize);
+    d->m_taskTree->start();
 }
 
 ExtraCompiler::ContentProvider ExtraCompiler::fromFileProvider() const