diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8b2b06ec..1e54cc5c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,7 +27,7 @@ jobs:
           coverage: none
 
       - name: PHP Lint
-        run: find lib tests -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l
+        run: find src tests -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l
 
   unit-tests:
     name: Unit tests
diff --git a/composer.json b/composer.json
index 7913a9cd..2d515072 100644
--- a/composer.json
+++ b/composer.json
@@ -16,13 +16,13 @@
         "codacy/coverage": "^1.4"
     },
     "autoload": {
-        "psr-4": { "Sabberworm\\CSS\\": "lib/Sabberworm/CSS/" }
+        "psr-4": { "Sabberworm\\CSS\\": "src/" }
     },
     "scripts": {
         "ci": [
             "@ci:static"
         ],
-        "ci:php:sniff": "@php ./.phive/phpcs.phar lib tests",
+        "ci:php:sniff": "@php ./.phive/phpcs.phar src tests",
         "ci:php:stan": "@php ./.phive/phpstan.phar",
         "ci:static": [
             "@ci:php:sniff",
@@ -31,7 +31,7 @@
         "fix:php": [
             "@fix:php:sniff"
         ],
-        "fix:php:sniff": "@php ./.phive/phpcbf.phar lib tests",
+        "fix:php:sniff": "@php ./.phive/phpcbf.phar src tests",
         "phpstan:baseline": "@php ./.phive/phpstan.phar --generate-baseline"
     }
 }
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index b0bdb0a4..f28b1ab6 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -3,5 +3,5 @@ parameters:
 		-
 			message: "#^Access to an undefined property Sabberworm\\\\CSS\\\\Parsing\\\\ParserState\\:\\:\\$oParserHelper\\.$#"
 			count: 1
-			path: lib/Sabberworm/CSS/Parsing/ParserState.php
+			path: src/Parsing/ParserState.php
 
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index e50e3f9e..765eb58f 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -9,8 +9,8 @@ parameters:
   level: 0
 
   scanDirectories:
-    - %currentWorkingDirectory%/lib/
+    - %currentWorkingDirectory%/src/
     - %currentWorkingDirectory%/tests/
   paths:
-    - %currentWorkingDirectory%/lib/
+    - %currentWorkingDirectory%/src/
     - %currentWorkingDirectory%/tests/
diff --git a/phpunit.xml b/phpunit.xml
index 6afca719..5f3dd458 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -9,7 +9,7 @@
 
     <filter>
         <whitelist>
-            <directory suffix=".php">lib/Sabberworm/CSS</directory>
+            <directory suffix=".php">src</directory>
         </whitelist>
     </filter>
 </phpunit>
diff --git a/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php b/src/CSSList/AtRuleBlockList.php
similarity index 100%
rename from lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
rename to src/CSSList/AtRuleBlockList.php
diff --git a/lib/Sabberworm/CSS/CSSList/CSSBlockList.php b/src/CSSList/CSSBlockList.php
similarity index 100%
rename from lib/Sabberworm/CSS/CSSList/CSSBlockList.php
rename to src/CSSList/CSSBlockList.php
diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/src/CSSList/CSSList.php
similarity index 100%
rename from lib/Sabberworm/CSS/CSSList/CSSList.php
rename to src/CSSList/CSSList.php
diff --git a/lib/Sabberworm/CSS/CSSList/Document.php b/src/CSSList/Document.php
similarity index 100%
rename from lib/Sabberworm/CSS/CSSList/Document.php
rename to src/CSSList/Document.php
diff --git a/lib/Sabberworm/CSS/CSSList/KeyFrame.php b/src/CSSList/KeyFrame.php
similarity index 100%
rename from lib/Sabberworm/CSS/CSSList/KeyFrame.php
rename to src/CSSList/KeyFrame.php
diff --git a/lib/Sabberworm/CSS/Comment/Comment.php b/src/Comment/Comment.php
similarity index 100%
rename from lib/Sabberworm/CSS/Comment/Comment.php
rename to src/Comment/Comment.php
diff --git a/lib/Sabberworm/CSS/Comment/Commentable.php b/src/Comment/Commentable.php
similarity index 100%
rename from lib/Sabberworm/CSS/Comment/Commentable.php
rename to src/Comment/Commentable.php
diff --git a/lib/Sabberworm/CSS/OutputFormat.php b/src/OutputFormat.php
similarity index 100%
rename from lib/Sabberworm/CSS/OutputFormat.php
rename to src/OutputFormat.php
diff --git a/lib/Sabberworm/CSS/Parser.php b/src/Parser.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parser.php
rename to src/Parser.php
diff --git a/lib/Sabberworm/CSS/Parsing/OutputException.php b/src/Parsing/OutputException.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parsing/OutputException.php
rename to src/Parsing/OutputException.php
diff --git a/lib/Sabberworm/CSS/Parsing/ParserState.php b/src/Parsing/ParserState.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parsing/ParserState.php
rename to src/Parsing/ParserState.php
diff --git a/lib/Sabberworm/CSS/Parsing/SourceException.php b/src/Parsing/SourceException.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parsing/SourceException.php
rename to src/Parsing/SourceException.php
diff --git a/lib/Sabberworm/CSS/Parsing/UnexpectedEOFException.php b/src/Parsing/UnexpectedEOFException.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parsing/UnexpectedEOFException.php
rename to src/Parsing/UnexpectedEOFException.php
diff --git a/lib/Sabberworm/CSS/Parsing/UnexpectedTokenException.php b/src/Parsing/UnexpectedTokenException.php
similarity index 100%
rename from lib/Sabberworm/CSS/Parsing/UnexpectedTokenException.php
rename to src/Parsing/UnexpectedTokenException.php
diff --git a/lib/Sabberworm/CSS/Property/AtRule.php b/src/Property/AtRule.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/AtRule.php
rename to src/Property/AtRule.php
diff --git a/lib/Sabberworm/CSS/Property/CSSNamespace.php b/src/Property/CSSNamespace.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/CSSNamespace.php
rename to src/Property/CSSNamespace.php
diff --git a/lib/Sabberworm/CSS/Property/Charset.php b/src/Property/Charset.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/Charset.php
rename to src/Property/Charset.php
diff --git a/lib/Sabberworm/CSS/Property/Import.php b/src/Property/Import.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/Import.php
rename to src/Property/Import.php
diff --git a/lib/Sabberworm/CSS/Property/KeyframeSelector.php b/src/Property/KeyframeSelector.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/KeyframeSelector.php
rename to src/Property/KeyframeSelector.php
diff --git a/lib/Sabberworm/CSS/Property/Selector.php b/src/Property/Selector.php
similarity index 100%
rename from lib/Sabberworm/CSS/Property/Selector.php
rename to src/Property/Selector.php
diff --git a/lib/Sabberworm/CSS/Renderable.php b/src/Renderable.php
similarity index 100%
rename from lib/Sabberworm/CSS/Renderable.php
rename to src/Renderable.php
diff --git a/lib/Sabberworm/CSS/Rule/Rule.php b/src/Rule/Rule.php
similarity index 100%
rename from lib/Sabberworm/CSS/Rule/Rule.php
rename to src/Rule/Rule.php
diff --git a/lib/Sabberworm/CSS/RuleSet/AtRuleSet.php b/src/RuleSet/AtRuleSet.php
similarity index 100%
rename from lib/Sabberworm/CSS/RuleSet/AtRuleSet.php
rename to src/RuleSet/AtRuleSet.php
diff --git a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php b/src/RuleSet/DeclarationBlock.php
similarity index 100%
rename from lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
rename to src/RuleSet/DeclarationBlock.php
diff --git a/lib/Sabberworm/CSS/RuleSet/RuleSet.php b/src/RuleSet/RuleSet.php
similarity index 100%
rename from lib/Sabberworm/CSS/RuleSet/RuleSet.php
rename to src/RuleSet/RuleSet.php
diff --git a/lib/Sabberworm/CSS/Settings.php b/src/Settings.php
similarity index 100%
rename from lib/Sabberworm/CSS/Settings.php
rename to src/Settings.php
diff --git a/lib/Sabberworm/CSS/Value/CSSFunction.php b/src/Value/CSSFunction.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/CSSFunction.php
rename to src/Value/CSSFunction.php
diff --git a/lib/Sabberworm/CSS/Value/CSSString.php b/src/Value/CSSString.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/CSSString.php
rename to src/Value/CSSString.php
diff --git a/lib/Sabberworm/CSS/Value/CalcFunction.php b/src/Value/CalcFunction.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/CalcFunction.php
rename to src/Value/CalcFunction.php
diff --git a/lib/Sabberworm/CSS/Value/CalcRuleValueList.php b/src/Value/CalcRuleValueList.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/CalcRuleValueList.php
rename to src/Value/CalcRuleValueList.php
diff --git a/lib/Sabberworm/CSS/Value/Color.php b/src/Value/Color.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/Color.php
rename to src/Value/Color.php
diff --git a/lib/Sabberworm/CSS/Value/LineName.php b/src/Value/LineName.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/LineName.php
rename to src/Value/LineName.php
diff --git a/lib/Sabberworm/CSS/Value/PrimitiveValue.php b/src/Value/PrimitiveValue.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/PrimitiveValue.php
rename to src/Value/PrimitiveValue.php
diff --git a/lib/Sabberworm/CSS/Value/RuleValueList.php b/src/Value/RuleValueList.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/RuleValueList.php
rename to src/Value/RuleValueList.php
diff --git a/lib/Sabberworm/CSS/Value/Size.php b/src/Value/Size.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/Size.php
rename to src/Value/Size.php
diff --git a/lib/Sabberworm/CSS/Value/URL.php b/src/Value/URL.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/URL.php
rename to src/Value/URL.php
diff --git a/lib/Sabberworm/CSS/Value/Value.php b/src/Value/Value.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/Value.php
rename to src/Value/Value.php
diff --git a/lib/Sabberworm/CSS/Value/ValueList.php b/src/Value/ValueList.php
similarity index 100%
rename from lib/Sabberworm/CSS/Value/ValueList.php
rename to src/Value/ValueList.php