diff --git a/tests/Unit/OccurrencesTest.php b/tests/Unit/OccurrencesTest.php
index 18c0b8ca8bac1068528c6804737bd01def2ad1d4..10cbde41f384cb48d37af53b3f61e86618578fac 100644
--- a/tests/Unit/OccurrencesTest.php
+++ b/tests/Unit/OccurrencesTest.php
@@ -21,21 +21,21 @@ final class OccurrencesTest extends TestCase
         $this->occurrences = new Occurrences();
     }
 
-    public function testShouldGetValidResponseFromGet()
+    public function testShouldGetValidResponseFromGet(): void
     {
         $response = $this->occurrences->get(1258202889);
 
         $this->assertEquals("Alfaroa Standl.", $response['scientificName']);
     }
 
-    public function testShouldGetValidResponseFromGetVerbatim()
+    public function testShouldGetValidResponseFromGetVerbatim(): void
     {
         $response = $this->occurrences->getVerbatim(1258202889);
 
         $this->assertEquals("Alfaroa Standl.", $response['http://rs.tdwg.org/dwc/terms/scientificName']);
     }
 
-    public function testShouldGetValidResponseFromGetFragment()
+    public function testShouldGetValidResponseFromGetFragment(): void
     {
         $response = $this->occurrences->getFragment(1258202889);
 
diff --git a/tests/Unit/SpeciesTest.php b/tests/Unit/SpeciesTest.php
index ef197474ccf008772dfbf2016b00114a98390627..dcc1bb01c3d3e9f63b8cbc8f439f243a6f635173 100644
--- a/tests/Unit/SpeciesTest.php
+++ b/tests/Unit/SpeciesTest.php
@@ -3,6 +3,7 @@
 namespace ResTelae\Gbif\Tests\Unit;
 
 use PHPUnit\Framework\TestCase;
+use ResTelae\Gbif\GbifException;
 use ResTelae\Gbif\Species;
 
 /**
@@ -21,20 +22,23 @@ final class SpeciesTest extends TestCase
         $this->species = new Species();
     }
 
-    public function testShouldThrowExceptionIfInvalidDataChoice()
+    public function testShouldThrowExceptionIfInvalidDataChoice(): void
     {
+        $this->expectException(GbifException::class);
         $this->expectExceptionMessage('Illegal choice for `data`');
         $this->species->nameUsage([], 'invalid');
     }
 
-    public function testShouldThrowExceptionIfNoDataKeyProvided()
+    public function testShouldThrowExceptionIfNoDataKeyProvided(): void
     {
+        $this->expectException(GbifException::class);
         $this->expectExceptionMessage('You must specify a key if `data` does not equal `all`');
         $this->species->nameUsage([], 'name');
     }
 
-    public function testShouldThrowExceptionOnRootDataIfNoUuidOrShortNameProvided()
+    public function testShouldThrowExceptionOnRootDataIfNoUuidOrShortNameProvided(): void
     {
+        $this->expectException(GbifException::class);
         $this->expectExceptionMessage('`uuid` and `short_name` cannot be both NULL if `data` equals "root"');
         $this->species->nameUsage([], 'root', '123');
     }
@@ -69,7 +73,7 @@ final class SpeciesTest extends TestCase
         $this->assertSame($expected['canonicalName'], $response['canonicalName']);
     }
 
-    public function testShouldGetValidResponseFromNameUsageByKey()
+    public function testShouldGetValidResponseFromNameUsageByKey(): void
     {
         $response = $this->species->nameUsageByKey(5231190);
 
@@ -78,7 +82,7 @@ final class SpeciesTest extends TestCase
         $this->assertEquals('Passer domesticus', $response['species']);
     }
 
-    public function testShouldGetValidResponseFromNameBackbone()
+    public function testShouldGetValidResponseFromNameBackbone(): void
     {
         $response = $this->species->nameBackbone(
             [
@@ -93,7 +97,7 @@ final class SpeciesTest extends TestCase
         $this->assertEquals('GENUS', $response['rank']);
     }
 
-    public function testShouldGetValidResponseFromNameLookup()
+    public function testShouldGetValidResponseFromNameLookup(): void
     {
         $response = $this->species->nameLookup(
             [
@@ -111,7 +115,7 @@ final class SpeciesTest extends TestCase
         $this->assertEquals('Puma', $response['results'][0]['canonicalName']);
     }
 
-    public function testShouldGetValidResponseFromNameSuggest()
+    public function testShouldGetValidResponseFromNameSuggest(): void
     {
         $response = $this->species->nameSuggest(
             [