diff --git a/src/auth/PhutilAmazonAuthAdapter.php b/src/auth/PhutilAmazonAuthAdapter.php
--- a/src/auth/PhutilAmazonAuthAdapter.php
+++ b/src/auth/PhutilAmazonAuthAdapter.php
@@ -63,7 +63,7 @@
 
   protected function loadOAuthAccountData() {
     $uri = new PhutilURI('https://api.amazon.com/user/profile');
-    $uri->setQueryParam('access_token', $this->getAccessToken());
+    $uri->replaceQueryParam('access_token', $this->getAccessToken());
 
     $future = new HTTPSFuture($uri);
     list($body) = $future->resolvex();
diff --git a/src/auth/PhutilDisqusAuthAdapter.php b/src/auth/PhutilDisqusAuthAdapter.php
--- a/src/auth/PhutilDisqusAuthAdapter.php
+++ b/src/auth/PhutilDisqusAuthAdapter.php
@@ -63,8 +63,8 @@
 
   protected function loadOAuthAccountData() {
     $uri = new PhutilURI('https://disqus.com/api/3.0/users/details.json');
-    $uri->setQueryParam('api_key', $this->getClientID());
-    $uri->setQueryParam('access_token', $this->getAccessToken());
+    $uri->replaceQueryParam('api_key', $this->getClientID());
+    $uri->replaceQueryParam('access_token', $this->getAccessToken());
     $uri = (string)$uri;
 
     $future = new HTTPSFuture($uri);
diff --git a/src/auth/PhutilFacebookAuthAdapter.php b/src/auth/PhutilFacebookAuthAdapter.php
--- a/src/auth/PhutilFacebookAuthAdapter.php
+++ b/src/auth/PhutilFacebookAuthAdapter.php
@@ -84,8 +84,8 @@
     );
 
     $uri = new PhutilURI('https://graph.facebook.com/me');
-    $uri->setQueryParam('access_token', $this->getAccessToken());
-    $uri->setQueryParam('fields', implode(',', $fields));
+    $uri->replaceQueryParam('access_token', $this->getAccessToken());
+    $uri->replaceQueryParam('fields', implode(',', $fields));
     list($body) = id(new HTTPSFuture($uri))->resolvex();
 
     $data = null;
diff --git a/src/auth/PhutilGitHubAuthAdapter.php b/src/auth/PhutilGitHubAuthAdapter.php
--- a/src/auth/PhutilGitHubAuthAdapter.php
+++ b/src/auth/PhutilGitHubAuthAdapter.php
@@ -51,7 +51,7 @@
 
   protected function loadOAuthAccountData() {
     $uri = new PhutilURI('https://api.github.com/user');
-    $uri->setQueryParam('access_token', $this->getAccessToken());
+    $uri->replaceQueryParam('access_token', $this->getAccessToken());
 
     $future = new HTTPSFuture($uri);
 
diff --git a/src/auth/PhutilGoogleAuthAdapter.php b/src/auth/PhutilGoogleAuthAdapter.php
--- a/src/auth/PhutilGoogleAuthAdapter.php
+++ b/src/auth/PhutilGoogleAuthAdapter.php
@@ -36,7 +36,7 @@
     // a 100x100px image.
     if ($uri !== null) {
       $uri = new PhutilURI($uri);
-      $uri->setQueryParam('sz', 100);
+      $uri->replaceQueryParam('sz', 100);
       $uri = (string)$uri;
     }
 
@@ -82,7 +82,7 @@
 
   protected function loadOAuthAccountData() {
     $uri = new PhutilURI('https://www.googleapis.com/userinfo/v2/me');
-    $uri->setQueryParam('access_token', $this->getAccessToken());
+    $uri->replaceQueryParam('access_token', $this->getAccessToken());
 
     $future = new HTTPSFuture($uri);
     list($status, $body) = $future->resolve();
diff --git a/src/auth/PhutilJIRAAuthAdapter.php b/src/auth/PhutilJIRAAuthAdapter.php
--- a/src/auth/PhutilJIRAAuthAdapter.php
+++ b/src/auth/PhutilJIRAAuthAdapter.php
@@ -142,19 +142,21 @@
   }
 
   public function newJIRAFuture($path, $method, $params = array()) {
-    $uri = new PhutilURI($this->getJIRAURI($path));
     if ($method == 'GET') {
-      $uri->setQueryParams($params);
-      $params = array();
+      $uri_params = $params;
+      $body_params = array();
     } else {
       // For other types of requests, JIRA expects the request body to be
       // JSON encoded.
-      $params = json_encode($params);
+      $uri_params = array();
+      $body_params = phutil_json_encode($params);
     }
 
+    $uri = new PhutilURI($this->getJIRAURI($path), $uri_params);
+
     // JIRA returns a 415 error if we don't provide a Content-Type header.
 
-    return $this->newOAuth1Future($uri, $params)
+    return $this->newOAuth1Future($uri, $body_params)
       ->setMethod($method)
       ->addHeader('Content-Type', 'application/json');
   }
diff --git a/src/auth/PhutilOAuth1AuthAdapter.php b/src/auth/PhutilOAuth1AuthAdapter.php
--- a/src/auth/PhutilOAuth1AuthAdapter.php
+++ b/src/auth/PhutilOAuth1AuthAdapter.php
@@ -154,7 +154,7 @@
     $this->readTokenAndTokenSecret($data);
 
     $authorize_token_uri = new PhutilURI($this->getAuthorizeTokenURI());
-    $authorize_token_uri->setQueryParam('oauth_token', $this->getToken());
+    $authorize_token_uri->replaceQueryParam('oauth_token', $this->getToken());
 
     return (string)$authorize_token_uri;
   }
diff --git a/src/auth/PhutilOAuthAuthAdapter.php b/src/auth/PhutilOAuthAuthAdapter.php
--- a/src/auth/PhutilOAuthAuthAdapter.php
+++ b/src/auth/PhutilOAuthAuthAdapter.php
@@ -21,13 +21,13 @@
 
   public function getAuthenticateURI() {
     $uri = new PhutilURI($this->getAuthenticateBaseURI());
-    $uri->setQueryParam('client_id', $this->getClientID());
-    $uri->setQueryParam('scope', $this->getScope());
-    $uri->setQueryParam('redirect_uri', $this->getRedirectURI());
-    $uri->setQueryParam('state', $this->getState());
+    $uri->replaceQueryParam('client_id', $this->getClientID());
+    $uri->replaceQueryParam('scope', $this->getScope());
+    $uri->replaceQueryParam('redirect_uri', $this->getRedirectURI());
+    $uri->replaceQueryParam('state', $this->getState());
 
     foreach ($this->getExtraAuthenticateParameters() as $key => $value) {
-      $uri->setQueryParam($key, $value);
+      $uri->replaceQueryParam($key, $value);
     }
 
     return (string)$uri;
diff --git a/src/auth/PhutilPhabricatorAuthAdapter.php b/src/auth/PhutilPhabricatorAuthAdapter.php
--- a/src/auth/PhutilPhabricatorAuthAdapter.php
+++ b/src/auth/PhutilPhabricatorAuthAdapter.php
@@ -80,7 +80,7 @@
 
   protected function loadOAuthAccountData() {
     $uri = id(new PhutilURI($this->getPhabricatorURI('api/user.whoami')))
-      ->setQueryParam('access_token', $this->getAccessToken());
+      ->replaceQueryParam('access_token', $this->getAccessToken());
     list($body) = id(new HTTPSFuture($uri))->resolvex();
 
     try {
diff --git a/src/auth/PhutilTwitterAuthAdapter.php b/src/auth/PhutilTwitterAuthAdapter.php
--- a/src/auth/PhutilTwitterAuthAdapter.php
+++ b/src/auth/PhutilTwitterAuthAdapter.php
@@ -55,11 +55,13 @@
 
   private function getUserInfo() {
     if ($this->userInfo === null) {
-      $uri = new PhutilURI('https://api.twitter.com/1.1/users/show.json');
-      $uri->setQueryParams(
-        array(
-          'user_id' => $this->getAccountID(),
-        ));
+      $params = array(
+        'user_id' => $this->getAccountID(),
+      );
+
+      $uri = new PhutilURI(
+        'https://api.twitter.com/1.1/users/show.json',
+        $params);
 
       $data = $this->newOAuth1Future($uri)
         ->setMethod('GET')
diff --git a/src/future/aws/PhutilAWSFuture.php b/src/future/aws/PhutilAWSFuture.php
--- a/src/future/aws/PhutilAWSFuture.php
+++ b/src/future/aws/PhutilAWSFuture.php
@@ -98,9 +98,8 @@
       $path = $this->getPath();
       $data = $this->getData();
 
-      $uri = id(new PhutilURI("https://{$host}/"))
-        ->setPath($path)
-        ->setQueryParams($params);
+      $uri = id(new PhutilURI("https://{$host}/", $params))
+        ->setPath($path);
 
       $future = id(new HTTPSFuture($uri, $data))
         ->setMethod($method);
diff --git a/src/future/oauth/PhutilOAuth1Future.php b/src/future/oauth/PhutilOAuth1Future.php
--- a/src/future/oauth/PhutilOAuth1Future.php
+++ b/src/future/oauth/PhutilOAuth1Future.php
@@ -183,7 +183,7 @@
 
     $sign_uri = clone $this->uri;
     $sign_uri->setFragment('');
-    $sign_uri->setQueryParams(array());
+    $sign_uri->removeAllQueryParams();
 
     $sign_uri->setProtocol(phutil_utf8_strtolower($sign_uri->getProtocol()));
     $protocol = $sign_uri->getProtocol();
diff --git a/src/future/slack/PhutilSlackFuture.php b/src/future/slack/PhutilSlackFuture.php
--- a/src/future/slack/PhutilSlackFuture.php
+++ b/src/future/slack/PhutilSlackFuture.php
@@ -48,7 +48,7 @@
 
       $uri = new PhutilURI('https://slack.com/');
       $uri->setPath('/api/'.$this->action);
-      $uri->setQueryParam('token', $this->accessToken);
+      $uri->replaceQueryParam('token', $this->accessToken);
 
       $future = new HTTPSFuture($uri);
       $future->setData($this->params);
diff --git a/src/future/twitch/PhutilTwitchFuture.php b/src/future/twitch/PhutilTwitchFuture.php
--- a/src/future/twitch/PhutilTwitchFuture.php
+++ b/src/future/twitch/PhutilTwitchFuture.php
@@ -48,7 +48,7 @@
 
       $uri = new PhutilURI('https://api.twitch.tv/');
       $uri->setPath('/kraken/'.ltrim($this->action, '/'));
-      $uri->setQueryParam('oauth_token', $this->accessToken);
+      $uri->replaceQueryParam('oauth_token', $this->accessToken);
 
       $future = new HTTPSFuture($uri);
       $future->setData($this->params);