diff --git a/src/Illuminate/Http/Client/PendingRequest.php b/src/Illuminate/Http/Client/PendingRequest.php
index 91ce36673a1..ac3ec779106 100644
--- a/src/Illuminate/Http/Client/PendingRequest.php
+++ b/src/Illuminate/Http/Client/PendingRequest.php
@@ -6,6 +6,7 @@
 use GuzzleHttp\Cookie\CookieJar;
 use GuzzleHttp\Exception\ConnectException;
 use GuzzleHttp\HandlerStack;
+use Illuminate\Support\Str;
 use Illuminate\Support\Traits\Macroable;
 
 class PendingRequest
@@ -466,8 +467,22 @@ public function send(string $method, string $url, array $options = [])
 
         return retry($this->tries ?? 1, function () use ($method, $url, $options) {
             try {
+                $laravelData = $options[$this->bodyFormat] ?? $options['query'] ?? [];
+
+                // Attempt to parse query string on url if no request data found
+                $urlStr = Str::of($url);
+                if (! $laravelData && $method === 'GET' && $urlStr->contains('?')) {
+                    $laravelData = (string) $urlStr->after('?');
+                }
+
+                // If found data is a string then treat it as query parameters and parse them to an array
+                if (is_string($laravelData)) {
+                    parse_str($laravelData, $parsedData);
+                    $laravelData = is_array($parsedData) ? $parsedData : [];
+                }
+
                 return tap(new Response($this->buildClient()->request($method, $url, $this->mergeOptions([
-                    'laravel_data' => $options[$this->bodyFormat] ?? [],
+                    'laravel_data' => $laravelData,
                     'on_stats' => function ($transferStats) {
                         $this->transferStats = $transferStats;
                     },
diff --git a/src/Illuminate/Http/Client/Request.php b/src/Illuminate/Http/Client/Request.php
index 5cc7ae588dc..812fc4568e7 100644
--- a/src/Illuminate/Http/Client/Request.php
+++ b/src/Illuminate/Http/Client/Request.php
@@ -3,6 +3,7 @@
 namespace Illuminate\Http\Client;
 
 use ArrayAccess;
+use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
 use LogicException;
 
@@ -66,9 +67,15 @@ public function hasHeader($key, $value = null)
             return ! empty($this->request->getHeaders()[$key]);
         }
 
+        $headers = $this->headers();
+
+        if (! Arr::has($headers, $key)) {
+            return false;
+        }
+
         $value = is_array($value) ? $value : [$value];
 
-        return empty(array_diff($value, $this->headers()[$key]));
+        return empty(array_diff($value, $headers[$key]));
     }
 
     /**
@@ -79,7 +86,7 @@ public function hasHeader($key, $value = null)
      */
     public function header($key)
     {
-        return $this->headers()[$key];
+        return Arr::get($this->headers(), $key, [null]);
     }
 
     /**
diff --git a/tests/Http/HttpClientTest.php b/tests/Http/HttpClientTest.php
index 9df1b53676a..4648ea2a2a6 100644
--- a/tests/Http/HttpClientTest.php
+++ b/tests/Http/HttpClientTest.php
@@ -269,7 +269,8 @@ public function testGetWithArrayQueryParam()
         $this->factory->get('http://foo.com/get', ['foo' => 'bar']);
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?foo=bar';
+            return $request->url() === 'http://foo.com/get?foo=bar'
+                && $request['foo'] === 'bar';
         });
     }
 
@@ -280,7 +281,8 @@ public function testGetWithStringQueryParam()
         $this->factory->get('http://foo.com/get', 'foo=bar');
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?foo=bar';
+            return $request->url() === 'http://foo.com/get?foo=bar'
+                && $request['foo'] === 'bar';
         });
     }
 
@@ -291,7 +293,9 @@ public function testGetWithQuery()
         $this->factory->get('http://foo.com/get?foo=bar&page=1');
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?foo=bar&page=1';
+            return $request->url() === 'http://foo.com/get?foo=bar&page=1'
+                && $request['foo'] === 'bar'
+                && $request['page'] === '1';
         });
     }
 
@@ -302,7 +306,10 @@ public function testGetWithQueryWontEncode()
         $this->factory->get('http://foo.com/get?foo;bar;1;5;10&page=1');
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?foo;bar;1;5;10&page=1';
+            return $request->url() === 'http://foo.com/get?foo;bar;1;5;10&page=1'
+                && ! isset($request['foo'])
+                && ! isset($request['bar'])
+                && $request['page'] === '1';
         });
     }
 
@@ -313,7 +320,8 @@ public function testGetWithArrayQueryParamOverwrites()
         $this->factory->get('http://foo.com/get?foo=bar&page=1', ['hello' => 'world']);
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?hello=world';
+            return $request->url() === 'http://foo.com/get?hello=world'
+                && $request['hello'] === 'world';
         });
     }
 
@@ -324,7 +332,8 @@ public function testGetWithArrayQueryParamEncodes()
         $this->factory->get('http://foo.com/get', ['foo;bar; space test' => 'laravel']);
 
         $this->factory->assertSent(function (Request $request) {
-            return $request->url() === 'http://foo.com/get?foo%3Bbar%3B%20space%20test=laravel';
+            return $request->url() === 'http://foo.com/get?foo%3Bbar%3B%20space%20test=laravel'
+                && $request['foo;bar; space test'] === 'laravel';
         });
     }
 }