diff --git a/README b/README
index 405429a959..6af26af75d 100644
--- a/README
+++ b/README
@@ -29,11 +29,19 @@ To use this software, you must:
 	https://golang.org/doc/install
   for details or, if you are using gccgo, follow the instructions at
 	https://golang.org/doc/install/gccgo
-- Grab the code from the repository and install the proto package.
+- Grab the code from the repository and install the `proto` package.
   The simplest way is to run `go get -u github.com/golang/protobuf/protoc-gen-go`.
-  The compiler plugin, protoc-gen-go, will be installed in $GOBIN,
-  defaulting to $GOPATH/bin.  It must be in your $PATH for the protocol
-  compiler, protoc, to find it.
+  The compiler plugin, `protoc-gen-go`, will be installed in `$GOPATH/bin`
+  unless `$GOBIN` is set. It must be in your `$PATH` for the protocol
+  compiler, `protoc`, to find it.
+- If you need a particular version of `protoc-gen-go` (e.g., to match your
+  `proto` package version), one option is
+  ```shell
+  GIT_TAG="v1.2.0" # change as needed
+  go get -d -u github.com/golang/protobuf/protoc-gen-go
+  git -C "$(go env GOPATH)"/src/github.com/golang/protobuf checkout $GIT_TAG
+  go install github.com/golang/protobuf/protoc-gen-go
+  ```
 
 This software has two parts: a 'protocol compiler plugin' that
 generates Go source files that, once compiled, can access and manage
diff --git a/types/duration.go b/types/duration.go
index 475d61f1db..979b8e78a4 100644
--- a/types/duration.go
+++ b/types/duration.go
@@ -80,7 +80,7 @@ func DurationFromProto(p *Duration) (time.Duration, error) {
 		return 0, fmt.Errorf("duration: %#v is out of range for time.Duration", p)
 	}
 	if p.Nanos != 0 {
-		d += time.Duration(p.Nanos)
+		d += time.Duration(p.Nanos) * time.Nanosecond
 		if (d < 0) != (p.Nanos < 0) {
 			return 0, fmt.Errorf("duration: %#v is out of range for time.Duration", p)
 		}
diff --git a/types/timestamp.go b/types/timestamp.go
index 7ae54d8b3f..232ada57ce 100644
--- a/types/timestamp.go
+++ b/types/timestamp.go
@@ -109,11 +109,9 @@ func TimestampNow() *Timestamp {
 // TimestampProto converts the time.Time to a google.protobuf.Timestamp proto.
 // It returns an error if the resulting Timestamp is invalid.
 func TimestampProto(t time.Time) (*Timestamp, error) {
-	seconds := t.Unix()
-	nanos := int32(t.Sub(time.Unix(seconds, 0)))
 	ts := &Timestamp{
-		Seconds: seconds,
-		Nanos:   nanos,
+		Seconds: t.Unix(),
+		Nanos:   int32(t.Nanosecond()),
 	}
 	if err := validateTimestamp(ts); err != nil {
 		return nil, err