diff --git a/datafusion/proto-common/gen/src/main.rs b/datafusion/proto-common/gen/src/main.rs
index 2cbe2afa5488..02e1ecf00bab 100644
--- a/datafusion/proto-common/gen/src/main.rs
+++ b/datafusion/proto-common/gen/src/main.rs
@@ -17,9 +17,6 @@
 
 use std::path::Path;
 
-type Error = Box<dyn std::error::Error>;
-type Result<T, E = Error> = std::result::Result<T, E>;
-
 fn main() -> Result<(), String> {
     let proto_dir = Path::new("proto");
     let proto_path = Path::new("proto/datafusion_common.proto");
diff --git a/datafusion/proto/gen/src/main.rs b/datafusion/proto/gen/src/main.rs
index be61ff58fa8d..7f163162035c 100644
--- a/datafusion/proto/gen/src/main.rs
+++ b/datafusion/proto/gen/src/main.rs
@@ -17,9 +17,6 @@
 
 use std::path::Path;
 
-type Error = Box<dyn std::error::Error>;
-type Result<T, E = Error> = std::result::Result<T, E>;
-
 fn main() -> Result<(), String> {
     let proto_dir = Path::new("datafusion/proto");
     let proto_path = Path::new("datafusion/proto/proto/datafusion.proto");
@@ -29,7 +26,6 @@ fn main() -> Result<(), String> {
     let descriptor_path = proto_dir.join("proto/proto_descriptor.bin");
 
     prost_build::Config::new()
-        .protoc_arg("--experimental_allow_proto3_optional")
         .file_descriptor_set_path(&descriptor_path)
         .out_dir(out_dir)
         .compile_well_known_types()