diff --git a/args.go b/args.go
index e55b274..98e280d 100644
--- a/args.go
+++ b/args.go
@@ -299,7 +299,7 @@ func unhex(c byte) int {
 
 func appendQuotedArg(dst, v []byte) []byte {
 	for _, c := range v {
-		if c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '/' {
+		if c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '/' || c == '.' {
 			dst = append(dst, c)
 		} else {
 			dst = append(dst, '%', hexChar(c>>4), hexChar(c&15))
diff --git a/args_test.go b/args_test.go
index c72a49c..ff6f739 100644
--- a/args_test.go
+++ b/args_test.go
@@ -29,7 +29,7 @@ func TestArgsString(t *testing.T) {
 	testArgsString(t, &a, "foo=bar")
 	testArgsString(t, &a, "foo=bar&baz=sss")
 	testArgsString(t, &a, "")
-	testArgsString(t, &a, "f%20o=xxx%D0%BF%D1%80%D0%B8%D0%B2%D0%B5aaa&sdf=ss")
+	testArgsString(t, &a, "f%20o=x.x/x%D0%BF%D1%80%D0%B8%D0%B2%D0%B5aaa&sdf=ss")
 	testArgsString(t, &a, "=asdfsdf")
 }