diff --git a/phpunit.xml b/phpunit.xml
index 4933682..885b081 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -2,7 +2,7 @@
 <phpunit
     backupGlobals="false"
     backupStaticAttributes="false"
-    bootstrap="_Tests/bootstrap.php"
+    bootstrap="tests/bootstrap.php"
     colors="true"
     convertErrorsToExceptions="true"
     convertNoticesToExceptions="true"
@@ -18,14 +18,14 @@
 >
     <testsuites>
         <testsuite name="Volcanus_Validation">
-            <directory suffix="Test.php">./_Tests/Volcanus/Validation/Test/</directory>
+            <directory suffix="Test.php">./tests/Volcanus/Validation/Test/</directory>
         </testsuite>
     </testsuites>
     <filter>
         <whitelist>
             <directory>./src</directory>
             <exclude>
-                <directory>./_Tests</directory>
+                <directory>./tests</directory>
                 <directory>./vendor</directory>
             </exclude>
         </whitelist>
diff --git a/testrunner.yml b/testrunner.yml
index 0dba232..48f83f0 100644
--- a/testrunner.yml
+++ b/testrunner.yml
@@ -3,12 +3,12 @@ general:
   test_targets:
     recursive: true
     resources:
-      - _Tests
+      - tests
   autotest:
     enabled: false
     watch_dirs:
       - src
-      - _Tests
+      - tests
   notify: true
 
 phpunit:
diff --git a/_Tests/Volcanus/Validation/Test/Checker/AbstractCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/AbstractCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/AbstractCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/AbstractCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/AcceptCharactersCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/AcceptCharactersCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/AcceptCharactersCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/AcceptCharactersCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/AlnumCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/AlnumCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/AlnumCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/AlnumCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/AlphaCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/AlphaCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/AlphaCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/AlphaCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/ArraySizeCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/ArraySizeCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/ArraySizeCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/ArraySizeCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/ChoiceCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/ChoiceCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/ChoiceCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/ChoiceCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/CompareCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/CompareCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/CompareCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/CompareCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/DateCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/DateCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/DateCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/DateCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/DatetimeCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/DatetimeCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/DatetimeCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/DatetimeCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/DigitCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/DigitCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/DigitCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/DigitCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/EmailCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/EmailCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/EmailCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/EmailCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/FixedLengthCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/FixedLengthCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/FixedLengthCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/FixedLengthCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/FloatCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/FloatCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/FloatCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/FloatCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/GraphCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/GraphCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/GraphCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/GraphCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/IntCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/IntCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/IntCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/IntCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/KanaCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/KanaCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/KanaCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/KanaCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/MaxLengthCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/MaxLengthCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/MaxLengthCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/MaxLengthCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/MaxValueCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/MaxValueCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/MaxValueCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/MaxValueCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/MinLengthCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/MinLengthCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/MinLengthCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/MinLengthCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/MinValueCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/MinValueCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/MinValueCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/MinValueCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/NotEmptyCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/NotEmptyCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/NotEmptyCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/NotEmptyCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/PhoneCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/PhoneCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/PhoneCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/PhoneCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/PostcodeCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/PostcodeCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/PostcodeCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/PostcodeCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/TextCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/TextCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/TextCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/TextCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/Checker/UriCheckerTest.php b/tests/Volcanus/Validation/Test/Checker/UriCheckerTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/Checker/UriCheckerTest.php
rename to tests/Volcanus/Validation/Test/Checker/UriCheckerTest.php
diff --git a/_Tests/Volcanus/Validation/Test/ContextTest.php b/tests/Volcanus/Validation/Test/ContextTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/ContextTest.php
rename to tests/Volcanus/Validation/Test/ContextTest.php
diff --git a/_Tests/Volcanus/Validation/Test/ErrorTest.php b/tests/Volcanus/Validation/Test/ErrorTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/ErrorTest.php
rename to tests/Volcanus/Validation/Test/ErrorTest.php
diff --git a/_Tests/Volcanus/Validation/Test/ResultTest.php b/tests/Volcanus/Validation/Test/ResultTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/ResultTest.php
rename to tests/Volcanus/Validation/Test/ResultTest.php
diff --git a/_Tests/Volcanus/Validation/Test/UtilTest.php b/tests/Volcanus/Validation/Test/UtilTest.php
similarity index 100%
rename from _Tests/Volcanus/Validation/Test/UtilTest.php
rename to tests/Volcanus/Validation/Test/UtilTest.php
diff --git a/_Tests/bootstrap.php b/tests/bootstrap.php
similarity index 100%
rename from _Tests/bootstrap.php
rename to tests/bootstrap.php