diff --git a/README.md b/README.md
index 81c1083..5baa60f 100644
--- a/README.md
+++ b/README.md
@@ -14,12 +14,13 @@ This program accepts messages using JSON encoding, which is much more friendly f
 humans and scripts.
 
 With this tool you can also browse the schema for gRPC services, either by querying
-a server that supports [service reflection](https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1alpha/reflection.proto)
-or by loading in "protoset" files (files that contain encoded file
+a server that supports [service reflection](https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1alpha/reflection.proto),
+by reading proto source files, or by loading in compiled "protoset" files (files that contain encoded file
 [descriptor protos](https://github.com/google/protobuf/blob/master/src/google/protobuf/descriptor.proto)).
 In fact, the way the tool transforms JSON request data into a binary encoded protobuf
 is using that very same schema. So, if the server you interact with does not support
-reflection, you will need to build "protoset" files that `grpcurl` can use.
+reflection, you will either need the proto source files that define the service or need
+protoset files that `grpcurl` can use.
 
 This repo also provides a library package, `github.com/fullstorydev/grpcurl`, that has
 functions for simplifying the construction of other command-line tools that dynamically