diff --git a/src/proto_demo/lib_protocol/src/main.ml b/src/proto_demo/lib_protocol/src/main.ml
index 70df5db2f..99459eb6b 100644
--- a/src/proto_demo/lib_protocol/src/main.ml
+++ b/src/proto_demo/lib_protocol/src/main.ml
@@ -37,8 +37,6 @@ type operation = {
   protocol_data: operation_data ;
 }
 
-let max_operation_data_length = 42
-
 let max_block_length = 42
 let validation_passes = []
 let acceptable_passes _op = []