diff --git a/java_gen/templates/of_interface.java b/java_gen/templates/of_interface.java
index 8c9bf25..98d7b9e 100644
--- a/java_gen/templates/of_interface.java
+++ b/java_gen/templates/of_interface.java
@@ -50,7 +50,7 @@
 //:: for prop in msg.members:
         ${prop.java_type.public_type} ${prop.getter_name}()${ "" if prop.is_universal else " throws UnsupportedOperationException"};
 //:: if prop.is_writeable:
-        Builder ${prop.setter_name}(${prop.java_type.public_type} ${prop.name})${ "" if prop.is_universal else " throws UnsupportedOperationException"};
+        Builder${msg.type_variable} ${prop.setter_name}(${prop.java_type.public_type} ${prop.name})${ "" if prop.is_universal else " throws UnsupportedOperationException"};
 //:: #endif
 //:: #endfor
     }