diff --git a/src/Value/CSSFunction.php b/src/Value/CSSFunction.php
index 5941b4b3..306df768 100644
--- a/src/Value/CSSFunction.php
+++ b/src/Value/CSSFunction.php
@@ -17,19 +17,19 @@
 class CSSFunction extends ValueList
 {
     /**
-     * @var string
+     * @var non-empty-string
      *
      * @internal since 8.8.0
      */
     protected $name;
 
     /**
-     * @param string $name
-     * @param RuleValueList|array<array-key, Value|string> $arguments
-     * @param string $separator
+     * @param non-empty-string $name
+     * @param RuleValueList|array<Value|string> $arguments
+     * @param non-empty-string $separator
      * @param int<0, max> $lineNumber
      */
-    public function __construct($name, $arguments, $separator = ',', int $lineNumber = 0)
+    public function __construct(string $name, $arguments, string $separator = ',', int $lineNumber = 0)
     {
         if ($arguments instanceof RuleValueList) {
             $separator = $arguments->getListSeparator();
@@ -82,25 +82,25 @@ private static function parseArguments(ParserState $parserState)
     }
 
     /**
-     * @return string
+     * @return non-empty-string
      */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
 
     /**
-     * @param string $name
+     * @param non-empty-string $name
      */
-    public function setName($name): void
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
 
     /**
-     * @return array<array-key, Value|string>
+     * @return array<Value|string>
      */
-    public function getArguments()
+    public function getArguments(): array
     {
         return $this->components;
     }
diff --git a/src/Value/Color.php b/src/Value/Color.php
index f6eeaa60..5f7829e8 100644
--- a/src/Value/Color.php
+++ b/src/Value/Color.php
@@ -217,9 +217,9 @@ public function setColor(array $colorValues): void
     }
 
     /**
-     * @return string
+     * @return non-empty-string
      */
-    public function getColorDescription()
+    public function getColorDescription(): string
     {
         return $this->getName();
     }
diff --git a/src/Value/RuleValueList.php b/src/Value/RuleValueList.php
index 9e505979..414d775c 100644
--- a/src/Value/RuleValueList.php
+++ b/src/Value/RuleValueList.php
@@ -12,7 +12,7 @@
 class RuleValueList extends ValueList
 {
     /**
-     * @param string $separator
+     * @param non-empty-string $separator
      * @param int<0, max> $lineNumber
      */
     public function __construct($separator = ',', int $lineNumber = 0)
diff --git a/src/Value/Value.php b/src/Value/Value.php
index a81ab472..3432b18c 100644
--- a/src/Value/Value.php
+++ b/src/Value/Value.php
@@ -32,7 +32,7 @@ public function __construct(int $lineNumber = 0)
     }
 
     /**
-     * @param array<array-key, string> $listDelimiters
+     * @param array<non-empty-string> $listDelimiters
      *
      * @return Value|string
      *
@@ -43,7 +43,7 @@ public function __construct(int $lineNumber = 0)
      */
     public static function parseValue(ParserState $parserState, array $listDelimiters = [])
     {
-        /** @var array<int, Value|string> $stack */
+        /** @var list<Value|string> $stack */
         $stack = [];
         $parserState->consumeWhiteSpace();
         //Build a list of delimiters and parsed values
diff --git a/src/Value/ValueList.php b/src/Value/ValueList.php
index b63b34ef..1d26b74d 100644
--- a/src/Value/ValueList.php
+++ b/src/Value/ValueList.php
@@ -15,14 +15,14 @@
 abstract class ValueList extends Value
 {
     /**
-     * @var array<array-key, Value|string>
+     * @var array<Value|string>
      *
      * @internal since 8.8.0
      */
     protected $components;
 
     /**
-     * @var string
+     * @var non-empty-string
      *
      * @internal since 8.8.0
      */
@@ -30,7 +30,7 @@ abstract class ValueList extends Value
 
     /**
      * @param array<Value|string>|Value|string $components
-     * @param string $separator
+     * @param non-empty-string $separator
      * @param int<0, max> $lineNumber
      */
     public function __construct($components = [], $separator = ',', int $lineNumber = 0)
@@ -67,11 +67,17 @@ public function setListComponents(array $components): void
         $this->components = $components;
     }
 
+    /**
+     * @return non-empty-string
+     */
     public function getListSeparator(): string
     {
         return $this->separator;
     }
 
+    /**
+     * @param non-empty-string $separator
+     */
     public function setListSeparator(string $separator): void
     {
         $this->separator = $separator;