diff --git a/mediapipe/framework/calculator_options.proto b/mediapipe/framework/calculator_options.proto
index 747e9c4a..3bc9f661 100644
--- a/mediapipe/framework/calculator_options.proto
+++ b/mediapipe/framework/calculator_options.proto
@@ -23,15 +23,13 @@ package mediapipe;
 option java_package = "com.google.mediapipe.proto";
 option java_outer_classname = "CalculatorOptionsProto";
 
-// Options for Calculators. Each Calculator implementation should
-// have its own options proto, which should look like this:
+// Options for Calculators, DEPRECATED. New calculators are encouraged to use
+// proto3 syntax options:
 //
 // message MyCalculatorOptions {
-//   extend CalculatorOptions {
-//     optional MyCalculatorOptions ext = <unique id, e.g. the CL#>;
-//   }
-//   optional string field_needed_by_my_calculator = 1;
-//   optional int32 another_field = 2;
+//   // proto3 does not expect "optional"
+//   string field_needed_by_my_calculator = 1;
+//   int32 another_field = 2;
 //   // etc
 // }
 message CalculatorOptions {