diff --git a/headerauth.go b/headerauth.go
index baa56b3c..dd50e6de 100644
--- a/headerauth.go
+++ b/headerauth.go
@@ -20,19 +20,21 @@ func ReadHeaderAuth(in string) (*HeaderAuth, error) {
 
 	i := strings.IndexByte(in, ' ')
 	if i < 0 {
-		return nil, fmt.Errorf("parse error")
+		return nil, fmt.Errorf("unable to find prefix (%s)", in)
 	}
 	a.Prefix, in = in[:i], in[i+1:]
 
-	r := regexp.MustCompile("^([a-z]+)=\"(.+?)\"(, )?")
+	r := regexp.MustCompile("^([a-z]+)=(\"(.+?)\"|([a-zA-Z0-9]+))(, )?")
 
 	for len(in) > 0 {
 		m := r.FindStringSubmatch(in)
 		if m == nil {
-			return nil, fmt.Errorf("parse error")
+			return nil, fmt.Errorf("unable to parse key-value (%s)", in)
 		}
 		in = in[len(m[0]):]
 
+		m[2] = strings.TrimPrefix(m[2], "\"")
+		m[2] = strings.TrimSuffix(m[2], "\"")
 		a.Values[m[1]] = m[2]
 	}
 
diff --git a/headerauth_test.go b/headerauth_test.go
index 47ce756c..46c83b59 100644
--- a/headerauth_test.go
+++ b/headerauth_test.go
@@ -22,7 +22,7 @@ var casesHeaderAuth = []struct {
 		},
 	},
 	{
-		"digest request",
+		"digest request 1",
 		`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale="FALSE"`,
 		&HeaderAuth{
 			Prefix: "Digest",
@@ -33,6 +33,18 @@ var casesHeaderAuth = []struct {
 			},
 		},
 	},
+	{
+		"digest request 2",
+		`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale=FALSE`,
+		&HeaderAuth{
+			Prefix: "Digest",
+			Values: map[string]string{
+				"realm": "4419b63f5e51",
+				"nonce": "8b84a3b789283a8bea8da7fa7d41f08b",
+				"stale": "FALSE",
+			},
+		},
+	},
 	{
 		"digest response",
 		`Digest username="aa", realm="bb", nonce="cc", uri="dd", response="ee"`,