diff --git a/cmd/markdown/main.go b/cmd/markdown/main.go
index 138ca37..393160c 100644
--- a/cmd/markdown/main.go
+++ b/cmd/markdown/main.go
@@ -10,7 +10,7 @@ import (
 )
 
 func main() {
-	var opt markdown.Options
+	var opt markdown.Extensions
 	flag.BoolVar(&opt.Notes, "notes", false, "turn on footnote syntax")
 	flag.BoolVar(&opt.Smart, "smart", false, "turn on smart quotes, dashes, and ellipses")
 	flag.BoolVar(&opt.Dlists, "dlists", false, "support definitions lists")
diff --git a/doc.go b/doc.go
index a4db798..ff7976b 100644
--- a/doc.go
+++ b/doc.go
@@ -12,7 +12,7 @@ Usage example:
 	)
 
 	func main() {
-		p := markdown.NewParser(&markdown.Options{Smart: true})
+		p := markdown.NewParser(&markdown.Extensions{Smart: true})
 
 		w := bufio.NewWriter(os.Stdout)
 		p.Markdown(os.Stdin, markdown.ToHTML(w))
diff --git a/markdown.go b/markdown.go
index 3be9516..601f940 100644
--- a/markdown.go
+++ b/markdown.go
@@ -34,8 +34,8 @@ const (
 	needParserIfaceVersion = parserIfaceVersion_16
 )
 
-// Markdown Options:
-type Options struct {
+// Markdown Extensions.
+type Extensions struct {
 	Smart        bool
 	Notes        bool
 	FilterHTML   bool
@@ -51,10 +51,10 @@ type Parser struct {
 // NewParser creates an instance of a parser. It can be reused
 // so that stacks and buffers need not be allocated anew for
 // each Markdown call.
-func NewParser(opt *Options) (p *Parser) {
+func NewParser(x *Extensions) (p *Parser) {
 	p = new(Parser)
-	if opt != nil {
-		p.yy.state.extension = *opt
+	if x != nil {
+		p.yy.state.extension = *x
 	}
 	p.yy.Init()
 	p.yy.state.heap.init(1024)
diff --git a/parser.leg b/parser.leg
index 8552735..eeafcf3 100644
--- a/parser.leg
+++ b/parser.leg
@@ -95,7 +95,7 @@ const (
 )
 
 type state struct {
-	extension		Options
+	extension		Extensions
 	heap	elemHeap
 	tree				*element	/* Results of parse. */
 	references			*element	/* List of link references found. */