diff --git a/tests/Unit/CSSList/AtRuleBlockListTest.php b/tests/Unit/CSSList/AtRuleBlockListTest.php
index 3b61e437..416c8819 100644
--- a/tests/Unit/CSSList/AtRuleBlockListTest.php
+++ b/tests/Unit/CSSList/AtRuleBlockListTest.php
@@ -144,4 +144,16 @@ public function isRootListAlwaysReturnsFalse(): void
 
         self::assertFalse($subject->isRootList());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new AtRuleBlockList('media');
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/CSSList/CSSBlockListTest.php b/tests/Unit/CSSList/CSSBlockListTest.php
index ce7e5447..50b6420e 100644
--- a/tests/Unit/CSSList/CSSBlockListTest.php
+++ b/tests/Unit/CSSList/CSSBlockListTest.php
@@ -471,4 +471,16 @@ public function getAllValuesWithSearchInFunctionArgumentsReturnsValuesInFunction
 
         self::assertSame([$value1, $value2], $result);
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new ConcreteCSSBlockList();
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/CSSList/DocumentTest.php b/tests/Unit/CSSList/DocumentTest.php
index 77e8aa81..c1d0f614 100644
--- a/tests/Unit/CSSList/DocumentTest.php
+++ b/tests/Unit/CSSList/DocumentTest.php
@@ -63,4 +63,16 @@ public function isRootListAlwaysReturnsTrue(): void
 
         self::assertTrue($subject->isRootList());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new Document();
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/CSSList/KeyFrameTest.php b/tests/Unit/CSSList/KeyFrameTest.php
index e191a440..b77f295d 100644
--- a/tests/Unit/CSSList/KeyFrameTest.php
+++ b/tests/Unit/CSSList/KeyFrameTest.php
@@ -108,4 +108,16 @@ public function getVendorKeyFrameByDefaultReturnsKeyframes(): void
 
         self::assertSame('keyframes', $subject->getVendorKeyFrame());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new KeyFrame();
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Property/KeyframeSelectorTest.php b/tests/Unit/Property/KeyframeSelectorTest.php
new file mode 100644
index 00000000..2f7cebac
--- /dev/null
+++ b/tests/Unit/Property/KeyframeSelectorTest.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Property;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Property\KeyframeSelector;
+
+/**
+ * @covers \Sabberworm\CSS\Property\KeyframeSelector
+ * @covers \Sabberworm\CSS\Property\Selector
+ */
+final class KeyframeSelectorTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new KeyframeSelector('a');
+
+        $subject->getArrayRepresentation();
+    }
+}
diff --git a/tests/Unit/RuleSet/AtRuleSetTest.php b/tests/Unit/RuleSet/AtRuleSetTest.php
index 0e3e0c97..74c60a04 100644
--- a/tests/Unit/RuleSet/AtRuleSetTest.php
+++ b/tests/Unit/RuleSet/AtRuleSetTest.php
@@ -30,4 +30,14 @@ public function implementsCSSListItem(): void
     {
         self::assertInstanceOf(CSSListItem::class, $this->subject);
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $this->subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/CSSFunctionTest.php b/tests/Unit/Value/CSSFunctionTest.php
new file mode 100644
index 00000000..8600c569
--- /dev/null
+++ b/tests/Unit/Value/CSSFunctionTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Value;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Value\CSSFunction;
+
+/**
+ * @covers \Sabberworm\CSS\Value\CSSFunction
+ * @covers \Sabberworm\CSS\Value\Value
+ * @covers \Sabberworm\CSS\Value\ValueList
+ */
+final class CSSFunctionTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new CSSFunction('filter', []);
+
+        $subject->getArrayRepresentation();
+    }
+}
diff --git a/tests/Unit/Value/CSSStringTest.php b/tests/Unit/Value/CSSStringTest.php
index c54ecdd7..d967d284 100644
--- a/tests/Unit/Value/CSSStringTest.php
+++ b/tests/Unit/Value/CSSStringTest.php
@@ -80,4 +80,16 @@ public function getLineNumberReturnsLineNumberProvidedToConstructor(): void
 
         self::assertSame($lineNumber, $subject->getLineNumber());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new CSSString('');
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/CalcFunctionTest.php b/tests/Unit/Value/CalcFunctionTest.php
index 65f23e13..330c43b7 100644
--- a/tests/Unit/Value/CalcFunctionTest.php
+++ b/tests/Unit/Value/CalcFunctionTest.php
@@ -198,4 +198,16 @@ private function parse(string $css): CalcFunction
         self::assertInstanceOf(CalcFunction::class, $function);
         return $function;
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new CalcFunction('calc', []);
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/CalcRuleValueListTest.php b/tests/Unit/Value/CalcRuleValueListTest.php
index 7314e3c5..a02c05f7 100644
--- a/tests/Unit/Value/CalcRuleValueListTest.php
+++ b/tests/Unit/Value/CalcRuleValueListTest.php
@@ -56,4 +56,16 @@ public function separatorAlwaysIsComma(): void
 
         self::assertSame(',', $subject->getListSeparator());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new CalcRuleValueList();
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/ColorTest.php b/tests/Unit/Value/ColorTest.php
index aaa25755..0311f9e5 100644
--- a/tests/Unit/Value/ColorTest.php
+++ b/tests/Unit/Value/ColorTest.php
@@ -471,4 +471,16 @@ public function throwsExceptionWithInvalidColor(string $color): void
 
         Color::parse(new ParserState($color, Settings::create()));
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new Color([]);
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/LineNameTest.php b/tests/Unit/Value/LineNameTest.php
new file mode 100644
index 00000000..e48670f8
--- /dev/null
+++ b/tests/Unit/Value/LineNameTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Value;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Value\LineName;
+
+/**
+ * @covers \Sabberworm\CSS\Value\LineName
+ * @covers \Sabberworm\CSS\Value\Value
+ * @covers \Sabberworm\CSS\Value\ValueList
+ */
+final class LineNameTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new LineName();
+
+        $subject->getArrayRepresentation();
+    }
+}
diff --git a/tests/Unit/Value/RuleValueListTest.php b/tests/Unit/Value/RuleValueListTest.php
new file mode 100644
index 00000000..e82d255a
--- /dev/null
+++ b/tests/Unit/Value/RuleValueListTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Value;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Value\RuleValueList;
+
+/**
+ * @covers \Sabberworm\CSS\Value\RuleValueList
+ * @covers \Sabberworm\CSS\Value\Value
+ * @covers \Sabberworm\CSS\Value\ValueList
+ */
+final class RuleValueListTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new RuleValueList();
+
+        $subject->getArrayRepresentation();
+    }
+}
diff --git a/tests/Unit/Value/SizeTest.php b/tests/Unit/Value/SizeTest.php
index c80f788c..fe86cf76 100644
--- a/tests/Unit/Value/SizeTest.php
+++ b/tests/Unit/Value/SizeTest.php
@@ -98,4 +98,16 @@ public function parsesUnit(string $unit): void
 
         self::assertSame($unit, $parsedSize->getUnit());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new Size(1);
+
+        $subject->getArrayRepresentation();
+    }
 }
diff --git a/tests/Unit/Value/URLTest.php b/tests/Unit/Value/URLTest.php
index 66654e64..8b4c0880 100644
--- a/tests/Unit/Value/URLTest.php
+++ b/tests/Unit/Value/URLTest.php
@@ -80,4 +80,16 @@ public function getLineNumberReturnsLineNumberProvidedToConstructor(): void
 
         self::assertSame($lineNumber, $subject->getLineNumber());
     }
+
+    /**
+     * @test
+     */
+    public function getArrayRepresentationThrowsException(): void
+    {
+        $this->expectException(\BadMethodCallException::class);
+
+        $subject = new URL(new CSSString('http://example.com'));
+
+        $subject->getArrayRepresentation();
+    }
 }