diff --git a/tests/Support/SupportStrTest.php b/tests/Support/SupportStrTest.php
index 552d9efd2dbd..e61ae5e4e249 100755
--- a/tests/Support/SupportStrTest.php
+++ b/tests/Support/SupportStrTest.php
@@ -98,6 +98,7 @@ public function testStringApa()
         $this->assertSame('To Kill a Mockingbird', Str::apa('To Kill A Mockingbird'));
 
         $this->assertSame('', Str::apa(''));
+        $this->assertSame('   ', Str::apa('   '));
     }
 
     public function testStringWithoutWordsDoesntProduceError()