diff --git a/src/ruby/bin/math.proto b/src/ruby/bin/math.proto
index e34ad5e9672791f1db5fc1a5e40973f95ab2cc40..311e148c021f66a8ed450e8258c60961314f546f 100755
--- a/src/ruby/bin/math.proto
+++ b/src/ruby/bin/math.proto
@@ -33,25 +33,25 @@ syntax = "proto3";
 package math;
 
 message DivArgs {
-  optional int64 dividend = 1;
-  optional int64 divisor = 2;
+  int64 dividend = 1;
+  int64 divisor = 2;
 }
 
 message DivReply {
-  optional int64 quotient = 1;
-  optional int64 remainder = 2;
+  int64 quotient = 1;
+  int64 remainder = 2;
 }
 
 message FibArgs {
-  optional int64 limit = 1;
+  int64 limit = 1;
 }
 
 message Num {
-  optional int64 num = 1;
+  int64 num = 1;
 }
 
 message FibReply {
-  optional int64 count = 1;
+  int64 count = 1;
 }
 
 service Math {