diff --git a/src/plugins/projectexplorer/customtoolchain.cpp b/src/plugins/projectexplorer/customtoolchain.cpp
index 0ad08032b48..be829531826 100644
--- a/src/plugins/projectexplorer/customtoolchain.cpp
+++ b/src/plugins/projectexplorer/customtoolchain.cpp
@@ -567,6 +567,7 @@ CustomToolChainConfigWidget::CustomToolChainConfigWidget(CustomToolChain *tc) :
     auto parserLayoutWidget = new QWidget;
     auto parserLayout = new QHBoxLayout(parserLayoutWidget);
     parserLayout->setContentsMargins(0, 0, 0, 0);
+    m_predefinedMacros->setPlaceholderText(tr("MACRO[=VALUE]"));
     m_predefinedMacros->setTabChangesFocus(true);
     m_predefinedMacros->setToolTip(tr("Each line defines a macro. Format is MACRO[=VALUE]."));
     m_headerPaths->setTabChangesFocus(true);