diff --git a/tests/AuthorizationTest.php b/tests/AuthorizationTest.php
index 0494525..89a2469 100644
--- a/tests/AuthorizationTest.php
+++ b/tests/AuthorizationTest.php
@@ -52,7 +52,7 @@ public function testAuthorizationProviderInteraction(): void
         ]);
 
         self::assertTrue($request->hasHeader('Authorization'), 'Authorization header not available');
-        self::assertEquals(['am9obmRvZTpzZWNyZXQ='], $request->getHeader('Authorization'));
+        self::assertSame('am9obmRvZTpzZWNyZXQ=', $request->getHeaderLine('Authorization'));
     }
 
     /**
diff --git a/tests/BasicTest.php b/tests/BasicTest.php
index 09d5b5d..3cc08c7 100644
--- a/tests/BasicTest.php
+++ b/tests/BasicTest.php
@@ -21,7 +21,7 @@ public function setUp(): void
     public function testApiHost(): void
     {
         $request = (new ApiRequestFactory($this->uri))->create(['resource' => 'user']);
-        self::assertEquals(['api.example.com'], $request->getHeader('Host'));
+        self::assertSame('api.example.com', $request->getHeaderLine('Host'));
     }
 
     public function testResourceInUrl(): void
@@ -29,7 +29,7 @@ public function testResourceInUrl(): void
         $request = (new ApiRequestFactory($this->uri))->create(['resource' => 'user']);
         $uri = $request->getUri();
 
-        self::assertEquals('/user/', $uri->getPath());
+        self::assertSame('/user/', $uri->getPath());
         self::assertStringNotContainsString('resource=', $uri->getQuery());
     }
 
diff --git a/tests/OptionTest.php b/tests/OptionTest.php
index 81e62c8..1900e49 100644
--- a/tests/OptionTest.php
+++ b/tests/OptionTest.php
@@ -23,7 +23,7 @@ public function testDefaultHttpRequestTimeout(): void
             ->getLastOptions();
 
         self::assertArrayHasKey('timeout', $options);
-        self::assertEquals(30, $options['timeout'], 'Default request timeout not set');
+        self::assertSame(30, $options['timeout'], 'Default request timeout not set');
     }
 
     public function testHttpRequestTimeoutOption(): void
@@ -39,6 +39,6 @@ public function testHttpRequestTimeoutOption(): void
         $client->execute(['resource' => 'user', 'id' => 1337]);
 
         $options = $mockHandler->getLastOptions();
-        self::assertEquals(5, $options['timeout'], 'Request timeout not set correctly');
+        self::assertSame(5, $options['timeout'], 'Request timeout not set correctly');
     }
 }
diff --git a/tests/ParameterTest.php b/tests/ParameterTest.php
index 973f9b1..5448676 100644
--- a/tests/ParameterTest.php
+++ b/tests/ParameterTest.php
@@ -30,7 +30,7 @@ public function setUp(): void
     public function testRequestParameter($name, $value, $encoded): void
     {
         $request = (new ApiRequestFactory($this->uri))->create(['resource' => 'user', $name => $value]);
-        self::assertEquals($name . '=' . $encoded, $request->getUri()->getQuery());
+        self::assertSame("{$name}={$encoded}", $request->getUri()->getQuery());
     }
 
     public static function parameters(): array
@@ -64,8 +64,8 @@ public function testSendRandomDataAsJson(): void
                 ]
             ]);
 
-        self::assertEquals(['application/json'], $request->getHeader('Content-Type'));
-        self::assertEquals('{"title":"Lorem Ipsum","author":{"id":1337}}', (string) $request->getBody());
+        self::assertSame('application/json', $request->getHeaderLine('Content-Type'));
+        self::assertSame('{"title":"Lorem Ipsum","author":{"id":1337}}', (string) $request->getBody());
     }
 
     public function testFormatParameter(): void
@@ -77,7 +77,7 @@ public function testFormatParameter(): void
                 'format'    => 'image'
             ]);
 
-        self::assertEquals('/user/1337.image', $request->getUri()->getPath());
+        self::assertSame('/user/1337.image', $request->getUri()->getPath());
         self::assertStringNotContainsString('format=', $request->getUri()->getQuery());
     }
 
@@ -102,7 +102,7 @@ public function testParameterOrder(): void
                 'filter'    => 'address.country.iso2=AT'
             ]);
 
-        self::assertEquals($expectedQueryString, $request->getUri()->getQuery());
+        self::assertSame($expectedQueryString, $request->getUri()->getQuery());
     }
 
     public function testAuthorizeParameter(): void
diff --git a/tests/RequestMethodTest.php b/tests/RequestMethodTest.php
index 1e1ea7c..27b4dec 100644
--- a/tests/RequestMethodTest.php
+++ b/tests/RequestMethodTest.php
@@ -26,7 +26,7 @@ public function setUp(): void
     public function testHttpGetMethod(array $params, string $message): void
     {
         $request = (new ApiRequestFactory($this->uri))->create($params);
-        self::assertEquals('GET', $request->getMethod(), $message);
+        self::assertSame('GET', $request->getMethod(), $message);
     }
 
     public function testHttpPostMethodForNonRetrieveActions(): void
@@ -34,8 +34,8 @@ public function testHttpPostMethodForNonRetrieveActions(): void
         $request = (new ApiRequestFactory($this->uri))
             ->create(['resource' => 'user', 'id' => 1337, 'action' => 'foobar']);
 
-        self::assertEquals('POST', $request->getMethod());
-        self::assertEquals('application/x-www-form-urlencoded', $request->getHeaderLine('Content-Type'));
+        self::assertSame('POST', $request->getMethod());
+        self::assertSame('application/x-www-form-urlencoded', $request->getHeaderLine('Content-Type'));
     }
 
     public function testHttpMethodParameterOverwrite(): void
@@ -43,7 +43,7 @@ public function testHttpMethodParameterOverwrite(): void
         $request = (new ApiRequestFactory($this->uri))
             ->create(['resource' => 'user', 'id' => 1337, 'httpMethod' => 'POST']);
 
-        self::assertEquals('POST', $request->getMethod());
+        self::assertSame('POST', $request->getMethod());
     }
 
     public function testHttpPostMethodForLongQueryStrings(): void
@@ -58,7 +58,7 @@ public function testHttpPostMethodForLongQueryStrings(): void
                 'page'      => 10
             ]);
 
-        self::assertEquals('POST', $request->getMethod());
+        self::assertSame('POST', $request->getMethod());
         self::assertStringContainsString(
             'select=',
             (string) $request->getBody(),
@@ -75,8 +75,8 @@ public function testHttpPostMethodForJsonData(): void
                 'data'      => ['title' => 'Lorem Ipsum']
             ]);
 
-        self::assertEquals('POST', $request->getMethod());
-        self::assertEquals('action=create', $request->getUri()->getQuery());
+        self::assertSame('POST', $request->getMethod());
+        self::assertSame('action=create', $request->getUri()->getQuery());
     }
 
     public static function defaultHttpMethodDataProvider(): array
diff --git a/tests/SelectSerializationTest.php b/tests/SelectSerializationTest.php
index 740c772..6058245 100644
--- a/tests/SelectSerializationTest.php
+++ b/tests/SelectSerializationTest.php
@@ -10,12 +10,12 @@ class SelectSerializationTest extends TestCase
 {
     public function testSimpleArray(): void
     {
-        self::assertEquals('id,name', stringify_select(['id', 'name']));
+        self::assertSame('id,name', stringify_select(['id', 'name']));
     }
 
     public function testNestedArrays(): void
     {
-        self::assertEquals('id,name,attr1,attr2', stringify_select(['id', 'name', ['attr1', 'attr2']]));
+        self::assertSame('id,name,attr1,attr2', stringify_select(['id', 'name', ['attr1', 'attr2']]));
     }
 
     public function testNestedArraysWithNonNumericKeys(): void
@@ -27,12 +27,12 @@ public function testNestedArraysWithNonNumericKeys(): void
             'attr'
         ];
 
-        self::assertEquals('id,name,subGroup[attr1,attr2],attr', stringify_select($spec));
+        self::assertSame('id,name,subGroup[attr1,attr2],attr', stringify_select($spec));
     }
 
     public function testNonNumericKeysWithNonArrayValues(): void
     {
-        self::assertEquals('subGroup.attr', stringify_select(['subGroup' => 'attr']));
+        self::assertSame('subGroup.attr', stringify_select(['subGroup' => 'attr']));
     }
 
     public function testNestedNonNumericArrays(): void
@@ -41,7 +41,7 @@ public function testNestedNonNumericArrays(): void
             'subGroup' => ['subSubGroup' => 'attr']
         ];
 
-        self::assertEquals('subGroup.subSubGroup.attr', stringify_select($spec));
+        self::assertSame('subGroup.subSubGroup.attr', stringify_select($spec));
     }
 
     public function testDeeplyNestedArrays(): void
@@ -62,12 +62,12 @@ public function testDeeplyNestedArrays(): void
         ];
 
         $selectString = 'id,name,subGroupA[id,name,subSubGroupA[attr1,attr2],subSubGroupB[subSubSubGroupA[attr1,attr2],subSubSubItem,subSubSubGroupB[attr1,attr2]]]';
-        self::assertEquals($selectString, stringify_select($spec));
+        self::assertSame($selectString, stringify_select($spec));
     }
 
     public function testSingleItemSubItemGroup(): void
     {
-        self::assertEquals('group.attr', stringify_select(['group' => ['attr']]));
+        self::assertSame('group.attr', stringify_select(['group' => ['attr']]));
     }
 
     public function testError(): void