diff --git a/core/polyfills.php b/core/polyfills.php
index 26231298..332f3112 100644
--- a/core/polyfills.php
+++ b/core/polyfills.php
@@ -406,6 +406,22 @@ function get_base_href(): string
     return $dir;
 }
 
+/**
+ * The opposite of the standard library's parse_url
+ */
+function unparse_url($parsed_url) {
+    $scheme   = isset($parsed_url['scheme']) ? $parsed_url['scheme'] . '://' : '';
+    $host     = isset($parsed_url['host']) ? $parsed_url['host'] : '';
+    $port     = isset($parsed_url['port']) ? ':' . $parsed_url['port'] : '';
+    $user     = isset($parsed_url['user']) ? $parsed_url['user'] : '';
+    $pass     = isset($parsed_url['pass']) ? ':' . $parsed_url['pass']  : '';
+    $pass     = ($user || $pass) ? "$pass@" : '';
+    $path     = isset($parsed_url['path']) ? $parsed_url['path'] : '';
+    $query    = !empty($parsed_url['query']) ? '?' . $parsed_url['query'] : '';
+    $fragment = !empty($parsed_url['fragment']) ? '#' . $parsed_url['fragment'] : '';
+    return "$scheme$user$pass$host$port$path$query$fragment";
+}
+
 function startsWith(string $haystack, string $needle): bool
 {
     $length = strlen($needle);
diff --git a/core/tests/urls.test.php b/core/tests/urls.test.php
index cec18284..0915bdcb 100644
--- a/core/tests/urls.test.php
+++ b/core/tests/urls.test.php
@@ -39,4 +39,22 @@ class UrlsTest extends TestCase
             make_http("https://foo.com")
         );
     }
+
+    public function test_modify_url()
+    {
+        $this->assertEquals(
+            "/foo/bar?a=3&b=2",
+            modify_url("/foo/bar?a=1&b=2", ["a"=>"3"])
+        );
+
+        $this->assertEquals(
+            "https://blah.com/foo/bar?b=2",
+            modify_url("https://blah.com/foo/bar?a=1&b=2", ["a"=>null])
+        );
+
+        $this->assertEquals(
+            "/foo/bar",
+            modify_url("/foo/bar?a=1&b=2", ["a"=>null, "b"=>null])
+        );
+    }
 }
diff --git a/core/urls.php b/core/urls.php
index a774b940..f4b1b721 100644
--- a/core/urls.php
+++ b/core/urls.php
@@ -1,7 +1,4 @@
 <?php declare(strict_types=1);
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
-* HTML Generation                                                           *
-\* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 class Link
 {
@@ -60,40 +57,24 @@ function make_link(?string $page=null, ?string $query=null): string
  */
 function modify_current_url(array $changes): string
 {
-    return modify_url($_SERVER['QUERY_STRING'], $changes);
+    return modify_url($_SERVER['REQUEST_URI'], $changes);
 }
 
 function modify_url(string $url, array $changes): string
 {
-    // SHIT: PHP is officially the worst web API ever because it does not
-    // have a built-in function to do this.
+    $parts = parse_url($url);
 
-    // SHIT: parse_str is magically retarded; not only is it a useless name, it also
-    // didn't return the parsed array, preferring to overwrite global variables with
-    // whatever data the user supplied. Thankfully, 4.0.3 added an extra option to
-    // give it an array to use...
     $params = [];
-    parse_str($url, $params);
-
-    if (isset($changes['q'])) {
-        $base = $changes['q'];
-        unset($changes['q']);
-    } else {
-        $base = _get_query();
-    }
-
-    if (isset($params['q'])) {
-        unset($params['q']);
-    }
-
+    if(isset($parts['query'])) parse_str($parts['query'], $params);
     foreach ($changes as $k => $v) {
         if (is_null($v) and isset($params[$k])) {
             unset($params[$k]);
         }
         $params[$k] = $v;
     }
+    $parts['query'] = http_build_query($params);
 
-    return make_link($base, http_build_query($params));
+    return unparse_url($parts);
 }
 
 
@@ -117,6 +98,10 @@ function make_http(string $link): string
     return $link;
 }
 
+/**
+ * If HTTP_REFERER is set, and not blacklisted, then return it
+ * Else return a default $dest
+ */
 function referer_or(string $dest, ?array $blacklist=null): string
 {
     if(empty($_SERVER['HTTP_REFERER'])) return $dest;
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 9d8dc0ce..8d3dfed2 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -112,6 +112,7 @@ abstract class ShimmiePHPUnitTestCase extends TestCase
         if (!$args) {
             $args = [];
         }
+        $_SERVER['REQUEST_URI'] = make_link($page_name, http_build_query($args));
         $_GET = $args;
         $_POST = [];
         $page = new Page();
@@ -129,6 +130,7 @@ abstract class ShimmiePHPUnitTestCase extends TestCase
         if (!$args) {
             $args = [];
         }
+        $_SERVER['REQUEST_URI'] = make_link($page_name);
         foreach ($args as $k=>$v) {
             if(is_array($v)) {
                 $args[$k] = $v;