diff --git a/frontmatter.go b/frontmatter.go
index 00f3167..175a399 100644
--- a/frontmatter.go
+++ b/frontmatter.go
@@ -11,13 +11,14 @@ func extractFrontmatter(b []byte) (frontmatter, content []byte) {
 	if !bytes.HasPrefix(b, frontmatterOpen) {
 		return nil, b
 	}
-	fm := b[len(frontmatterOpen):]
-	if len(fm) != 0 && fm[0] != '\n' {
+	if len(b) > len(frontmatterOpen) && b[len(frontmatterOpen)] != '\n' {
 		return nil, b
 	}
-	i := bytes.Index(fm, frontmatterClose)
+	b = b[len(frontmatterOpen):]
+
+	i := bytes.Index(b, frontmatterClose)
 	if i == -1 {
-		i = len(fm)
+		return b, nil
 	}
-	return fm[:i], b[len(frontmatterOpen)+len(fm):]
+	return b[:i], b[i+len(frontmatterClose):]
 }
diff --git a/frontmatter_test.go b/frontmatter_test.go
index f01431d..29e25a0 100644
--- a/frontmatter_test.go
+++ b/frontmatter_test.go
@@ -20,6 +20,11 @@ func TestExtractFrontmatter(t *testing.T) {
 			Frontmatter: "\na: b\nc: d",
 			Content:     "",
 		},
+		{
+			Raw:         "---\na: b\nc: d\n---\nHello, world!",
+			Frontmatter: "\na: b\nc: d",
+			Content:     "\nHello, world!",
+		},
 		{
 			Raw:         "# Hello, world!",
 			Frontmatter: "",