diff --git a/base/variant.cpp b/base/variant.cpp
index 330989a74..dfddc6ca4 100644
--- a/base/variant.cpp
+++ b/base/variant.cpp
@@ -28,7 +28,7 @@ using namespace icinga;
  */
 bool Variant::IsEmpty(void) const
 {
-	return (m_Value.empty());
+	return (m_Value.type() == typeid(boost::blank));
 }
 
 bool Variant::IsScalar(void) const
diff --git a/base/variant.h b/base/variant.h
index 4889518a5..7919f759f 100644
--- a/base/variant.h
+++ b/base/variant.h
@@ -105,7 +105,7 @@ public:
 	}
 
 private:
-	mutable boost::variant<double, string, Object::Ptr> m_Value;
+	mutable boost::variant<boost::blank, double, string, Object::Ptr> m_Value;
 };
 
 }