diff --git a/README.md b/README.md
index 9d389b4..dbc626b 100644
--- a/README.md
+++ b/README.md
@@ -67,9 +67,10 @@ use \Ovh\Api;
 use GuzzleHttp\Client;
 
 // Instantiate a custom Guzzle HTTP client and tweak it
-$client = new Client();
-$client->setDefaultOption('timeout', 1);
-$client->setDefaultOption('headers', ['User-Agent' => 'api_client']);
+$client = new Client([
+    'timeout' => 1,
+    'headers' => ['User-Agent' => 'api_client'],
+]);
 
 // Api credentials can be retrieved from the urls specified in the "Supported endpoints" section below.
 // Inject the custom HTTP client as the 5th argument of the constructor
diff --git a/src/Api.php b/src/Api.php
index be72110..5cf7324 100644
--- a/src/Api.php
+++ b/src/Api.php
@@ -264,6 +264,76 @@ protected function getTarget($path) : string
         return $endpoint . $path;
     }
 
+    /**
+     * @param mixed $value
+     *
+     * @return mixed
+     */
+    private function normalizeQueryValue($value)
+    {
+        if (is_array($value)) {
+            foreach ($value as $key => $item) {
+                $value[$key] = $this->normalizeQueryValue($item);
+            }
+
+            return $value;
+        }
+
+        if ($value === false) {
+            return 'false';
+        }
+
+        if ($value === true) {
+            return 'true';
+        }
+
+        if (is_float($value) && !is_finite($value)) {
+            return is_nan($value) ? 'NAN' : ($value > 0 ? 'INF' : '-INF');
+        }
+
+        return $value;
+    }
+
+    /**
+     * @param array<array-key, mixed> $headers
+     *
+     * @return array<array-key, mixed>
+     */
+    private function normalizeHeaders(array $headers): array
+    {
+        foreach ($headers as $name => $value) {
+            if (is_array($value)) {
+                if ($value === []) {
+                    unset($headers[$name]);
+                    continue;
+                }
+
+                foreach ($value as $index => $item) {
+                    if ($item === null || is_scalar($item) || (is_object($item) && method_exists($item, '__toString'))) {
+                        if (is_float($item) && !is_finite($item)) {
+                            $item = is_nan($item) ? 'NAN' : ($item > 0 ? 'INF' : '-INF');
+                        }
+
+                        $value[$index] = (string)$item;
+                    }
+                }
+
+                $headers[$name] = $value;
+                continue;
+            }
+
+            if ($value === null || is_scalar($value) || (is_object($value) && method_exists($value, '__toString'))) {
+                if (is_float($value) && !is_finite($value)) {
+                    $value = is_nan($value) ? 'NAN' : ($value > 0 ? 'INF' : '-INF');
+                }
+
+                $headers[$name] = (string)$value;
+            }
+        }
+
+        return $headers;
+    }
+
     /**
      * This is the main method of this wrapper. It will
      * sign a given query and return its result.
@@ -307,13 +377,8 @@ protected function rawCall($method, $path, $content = null, $is_authenticated =
 
             $query = array_merge($query, (array)$content);
 
-            // rewrite query args to properly dump true/false parameters
             foreach ($query as $key => $value) {
-                if ($value === false) {
-                    $query[$key] = "false";
-                } elseif ($value === true) {
-                    $query[$key] = "true";
-                }
+                $query[$key] = $this->normalizeQueryValue($value);
             }
 
             $query = \GuzzleHttp\Psr7\Query::build($query);
@@ -331,6 +396,7 @@ protected function rawCall($method, $path, $content = null, $is_authenticated =
         if (!is_array($headers)) {
             $headers = [];
         }
+        $headers = $this->normalizeHeaders($headers);
         $headers['Content-Type']      = 'application/json; charset=utf-8';
 
         if ($is_authenticated) {
@@ -342,7 +408,7 @@ protected function rawCall($method, $path, $content = null, $is_authenticated =
                 if (!isset($this->time_delta)) {
                     $this->calculateTimeDelta();
                 }
-                $now = time() + $this->time_delta;
+                $now = (string)(time() + $this->time_delta);
 
                 $headers['X-Ovh-Timestamp'] = $now;
 
diff --git a/tests/ApiTest.php b/tests/ApiTest.php
index 4e16bdd..8ade525 100644
--- a/tests/ApiTest.php
+++ b/tests/ApiTest.php
@@ -180,7 +180,7 @@ public function testClientCreation()
     public function testTimeDeltaCompute()
     {
         $client = new MockClient(
-            new Response(200, [], time() - 10),
+            new Response(200, [], (string)(time() - 10)),
             new Response(200, [], '{}'),
         );
 
@@ -326,6 +326,55 @@ public function testGetBooleanQueryArgs()
         $this->assertSame('https://eu.api.ovh.com/1.0/me/api/credential?dryRun=true&notDryRun=false', $req->getUri()->__toString());
     }
 
+    /**
+     * Test GET non-finite float query args
+     */
+    public function testGetNonFiniteFloatQueryArgs()
+    {
+        $client = new MockClient(new Response(200, [], '{}'));
+
+        $api = new Api(MOCK_APPLICATION_KEY, MOCK_APPLICATION_SECRET, 'ovh-eu', MOCK_CONSUMER_KEY, $client);
+        $api->get('/me/api/credential', ['nan' => NAN, 'inf' => INF, 'negativeInf' => -INF], null, false);
+
+        $calls = $client->calls;
+        $this->assertCount(1, $calls);
+
+        $req = $calls[0]['request'];
+        $this->assertSame('GET', $req->getMethod());
+        $this->assertSame('https://eu.api.ovh.com/1.0/me/api/credential?nan=NAN&inf=INF&negativeInf=-INF', $req->getUri()->__toString());
+    }
+
+    /**
+     * Test custom scalar headers
+     */
+    public function testCustomScalarHeaders()
+    {
+        $client = new MockClient(new Response(200, [], '{}'));
+
+        $api = new Api(MOCK_APPLICATION_KEY, MOCK_APPLICATION_SECRET, 'ovh-eu', MOCK_CONSUMER_KEY, $client);
+        $api->get('/me', null, [
+            'X-Int' => 123,
+            'X-Float' => 1.5,
+            'X-Bool-True' => true,
+            'X-Bool-False' => false,
+            'X-Null' => null,
+            'X-Array' => [123, true, null],
+            'X-Empty-Array' => [],
+        ], false);
+
+        $calls = $client->calls;
+        $this->assertCount(1, $calls);
+
+        $req = $calls[0]['request'];
+        $this->assertSame('123', $req->getHeaderLine('X-Int'));
+        $this->assertSame('1.5', $req->getHeaderLine('X-Float'));
+        $this->assertSame('1', $req->getHeaderLine('X-Bool-True'));
+        $this->assertSame('', $req->getHeaderLine('X-Bool-False'));
+        $this->assertSame('', $req->getHeaderLine('X-Null'));
+        $this->assertSame(['123', '1', ''], $req->getHeader('X-Array'));
+        $this->assertFalse($req->hasHeader('X-Empty-Array'));
+    }
+
     /**
      * Test valid provided endpoint
      */