diff --git a/src/core/pivarianttypes.cpp b/src/core/pivarianttypes.cpp
index 17688ec8..c7e19fdb 100644
--- a/src/core/pivarianttypes.cpp
+++ b/src/core/pivarianttypes.cpp
@@ -80,6 +80,12 @@ PIStringList PIVariantTypes::Enum::names() const {
 }
 
 
+PIVariantTypes::Enum & PIVariantTypes::Enum::operator <<(const PIVariantTypes::Enumerator & v) {
+	enum_list << v;
+	return *this;
+}
+
+
 PIVariantTypes::Enum & PIVariantTypes::Enum::operator <<(const PIString & v) {
 	enum_list << Enumerator(enum_list.size(), v);
 	return *this;
diff --git a/src/core/pivarianttypes.h b/src/core/pivarianttypes.h
index 0419f221..d9f4735c 100644
--- a/src/core/pivarianttypes.h
+++ b/src/core/pivarianttypes.h
@@ -51,6 +51,7 @@ namespace PIVariantTypes {
 		PIString enum_name;
 		PIString selected;
 		PIVector<Enumerator> enum_list;
+		Enum & operator <<(const Enumerator & v);
 		Enum & operator <<(const PIString & v);
 		Enum & operator <<(const PIStringList & v);
 	};