diff --git a/tests/lib/util/update-query-string.js b/tests/lib/util/update-query-string.js
new file mode 100644
index 0000000..1673bdc
--- /dev/null
+++ b/tests/lib/util/update-query-string.js
@@ -0,0 +1,21 @@
+var tape = require("tape")
+
+var updateQueryString = require("../../../lib/util/update-query-string")
+
+tape("test update query string method", function(t) {
+  var url = "http://example.com"
+  var updatedUrl = updateQueryString(url, "foo", "bar")
+
+  t.notEqual(url, updatedUrl, "update query string modifies URL")
+  t.equal(updatedUrl, url + "?foo=bar", "update query string creates new query string when no query string params are set")
+
+  updatedUrl = updateQueryString(updatedUrl, "foo", "baz")
+
+  t.equal(updatedUrl, url + "?foo=baz", "update query string updates existing query string param")
+
+  updatedUrl = updateQueryString(updatedUrl, "bar", "")
+
+  t.equal(updatedUrl, url + "?foo=baz&bar=", "update query string appends to existing query string")
+
+  t.end()
+})