diff --git a/params.go b/params.go
index 948783b..509a7c7 100644
--- a/params.go
+++ b/params.go
@@ -144,6 +144,13 @@
 						params.Add(tags[0], strconv.FormatInt(v.Int(), 10))
 					case reflect.Bool:
 						params.Add(tags[0], strconv.FormatBool(v.Bool()))
+					case reflect.Slice:
+						switch f.Type {
+						case reflect.TypeOf([]string{}):
+							for i := 0; i < v.Len(); i++ {
+								params.Add(tags[0], v.Index(i).String())
+							}
+						}
 					}
 				} else {
 					// Otherwise, the field is not set.
diff --git a/params_test.go b/params_test.go
index 4a2c9fe..f314a9e 100644
--- a/params_test.go
+++ b/params_test.go
@@ -35,15 +35,17 @@
 
 func TestBuildQueryString(t *testing.T) {
 	opts := struct {
-		J int    `q:"j"`
-		R string `q:"r,required"`
-		C bool   `q:"c"`
+		J int      `q:"j"`
+		R string   `q:"r,required"`
+		C bool     `q:"c"`
+		S []string `q:"s"`
 	}{
 		J: 2,
 		R: "red",
 		C: true,
+		S: []string{"one", "two", "three"},
 	}
-	expected := &url.URL{RawQuery: "c=true&j=2&r=red"}
+	expected := &url.URL{RawQuery: "c=true&j=2&r=red&s=one&s=two&s=three"}
 	actual, err := BuildQueryString(&opts)
 	if err != nil {
 		t.Errorf("Error building query string: %v", err)
@@ -51,9 +53,10 @@
 	th.CheckDeepEquals(t, expected, actual)
 
 	opts = struct {
-		J int    `q:"j"`
-		R string `q:"r,required"`
-		C bool   `q:"c"`
+		J int      `q:"j"`
+		R string   `q:"r,required"`
+		C bool     `q:"c"`
+		S []string `q:"s"`
 	}{
 		J: 2,
 		C: true,