diff --git a/README.md b/README.md
index 70b54f4..d8feed2 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,7 @@ The CLI supports the following flags/arguments:
 	- Format the matched files and output the diff to `stdout`
 * Lint (`-lint` flag)
 	- Format the matched files and output the diff to `stdout`, exits with status 1 if there are any differences
-* Stdin (just `-` or `/dev/stdin` argument)
+* Stdin (just `-` or `/dev/stdin` argument, or `-in` flag)
 	- Format the yaml data from `stdin` and output the result to `stdout`
 * Custom config path (`-conf` flag)
 	- If you would like to use a config not stored at `.yamlfmt` in the working directory, you can pass a relative or absolute path to a separate configuration file
diff --git a/cmd/yamlfmt/flags.go b/cmd/yamlfmt/flags.go
index d9b7a57..9fd6dbc 100644
--- a/cmd/yamlfmt/flags.go
+++ b/cmd/yamlfmt/flags.go
@@ -28,11 +28,12 @@ var (
 source yaml and formatted yaml.`)
 	flagDry *bool = flag.Bool("dry", false, `Perform a dry run; show the output of a formatting
 operation without performing it.`)
+	flagIn   *bool   = flag.Bool("in", false, "Format yaml read from stdin and output to stdout")
 	flagConf *string = flag.String("conf", "", "Read yamlfmt config from this path")
 )
 
 func getOperation() command.Operation {
-	if len(flag.Args()) == 1 && isStdin(flag.Args()[0]) {
+	if *flagIn || isStdinArg() {
 		return command.OperationStdin
 	}
 	if *flagLint {
@@ -44,7 +45,11 @@ func getOperation() command.Operation {
 	return command.OperationFormat
 }
 
-func isStdin(arg string) bool {
+func isStdinArg() bool {
+	if len(flag.Args()) != 1 {
+		return false
+	}
+	arg := flag.Args()[0]
 	return arg == "-" || arg == "/dev/stdin"
 }