diff --git a/lib/config/configcompilercontext.cpp b/lib/config/configcompilercontext.cpp
index 0f38cb33c..0404f7cb6 100644
--- a/lib/config/configcompilercontext.cpp
+++ b/lib/config/configcompilercontext.cpp
@@ -113,6 +113,8 @@ void ConfigCompilerContext::LinkItems(void)
 {
 	SetContext(this);
 
+	Log(LogInformation, "config", "Linking config items...");
+
 	BOOST_FOREACH(const ConfigItem::Ptr& item, m_Items) {
 		item->Link();
 	}
@@ -124,6 +126,8 @@ void ConfigCompilerContext::ValidateItems(void)
 {
 	SetContext(this);
 
+	Log(LogInformation, "config", "Validating config items...");
+
 	BOOST_FOREACH(const ConfigItem::Ptr& item, m_Items) {
 		ConfigType::Ptr ctype;
 
diff --git a/lib/config/expression.cpp b/lib/config/expression.cpp
index bb884fd69..397bf2013 100644
--- a/lib/config/expression.cpp
+++ b/lib/config/expression.cpp
@@ -33,6 +33,7 @@ Expression::Expression(const String& key, ExpressionOperator op,
     const Value& value, const DebugInfo& debuginfo)
 	: m_Key(key), m_Operator(op), m_Value(value), m_DebugInfo(debuginfo)
 {
+	ASSERT(op != OperatorExecute || value.IsObjectType<ExpressionList>());
 }
 
 void Expression::Execute(const Dictionary::Ptr& dictionary) const