diff --git a/src/leaf_data_type.cpp b/src/leaf_data_type.cpp
index 29fb355..b7a3876 100644
--- a/src/leaf_data_type.cpp
+++ b/src/leaf_data_type.cpp
@@ -100,4 +100,8 @@
 {
     return true;
 }
+bool Empty::operator==(const Empty&) const
+{
+    return true;
+}
 }