diff --git a/CHANGELOG.md b/CHANGELOG.md
index d579019..a89330b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,14 @@ See [GitHub releases](https://github.com/mll-lab/laravel-utils/releases).
 
 ## Unreleased
 
+### Added
+
+- Add `MLL\LaravelUtils\ModelStates\MermaidStateConfigValidator`
+
+### Removed
+
+- Remove `MLL\LaravelUtils\ModelStates\HasStateManager::generateMermaidGraphAsString`
+
 ## v6.0.0
 
 ### Changed
diff --git a/src/ModelStates/HasStateManager.php b/src/ModelStates/HasStateManager.php
index 22f0741..057b76e 100644
--- a/src/ModelStates/HasStateManager.php
+++ b/src/ModelStates/HasStateManager.php
@@ -3,9 +3,6 @@
 namespace MLL\LaravelUtils\ModelStates;
 
 use Illuminate\Database\Eloquent\Relations\MorphOne;
-use JBZoo\MermaidPHP\Graph;
-use JBZoo\MermaidPHP\Link;
-use JBZoo\MermaidPHP\Node;
 use MLL\LaravelUtils\ModelStates\Exceptions\UnknownStateException;
 
 trait HasStateManager
@@ -63,44 +60,6 @@ public function stateManager(): MorphOne
         );
     }
 
-    public function generateMermaidGraphAsString(): string
-    {
-        $config = $this->stateClassConfig();
-
-        $graph = (new Graph(['abc_order' => true]))
-            ->addStyle('linkStyle default interpolate basis');
-
-        $possibleStateInstances = array_map(
-            static fn (string $stateClass): State => new $stateClass(),
-            $config->possibleStates(),
-        );
-
-        foreach ($possibleStateInstances as $state) {
-            $graph->addNode(new Node($state::name()));
-        }
-
-        foreach ($possibleStateInstances as $state) {
-            foreach ($config->possibleNextStates($state) as $possibleNextState) {
-                $sourceNode = $graph->getNode($state::name());
-                $targetNode = $graph->getNode($possibleNextState::name());
-
-                if ($sourceNode instanceof Node && $targetNode instanceof Node) {
-                    $transition = $config->transition($state::class, $possibleNextState::class);
-                    assert($transition !== null);
-
-                    $reflectionClass = new \ReflectionClass($transition);
-                    $transitionName = $reflectionClass->getName() === DefaultTransition::class
-                        ? ''
-                        : $reflectionClass->getShortName();
-
-                    $graph->addLink(new Link($sourceNode, $targetNode, $transitionName));
-                }
-            }
-        }
-
-        return $graph->__toString();
-    }
-
     public function stateClassConfig(): StateConfig
     {
         return $this->stateClass()::config();
diff --git a/src/ModelStates/MermaidStateConfigValidator.php b/src/ModelStates/MermaidStateConfigValidator.php
new file mode 100644
index 0000000..195f51d
--- /dev/null
+++ b/src/ModelStates/MermaidStateConfigValidator.php
@@ -0,0 +1,66 @@
+<?php declare(strict_types=1);
+
+namespace MLL\LaravelUtils\ModelStates;
+
+use JBZoo\MermaidPHP\Graph;
+use JBZoo\MermaidPHP\Link;
+use JBZoo\MermaidPHP\Node;
+use PHPUnit\Framework\Assert;
+
+/** Requires the package jbzoo/mermaid-php. */
+class MermaidStateConfigValidator
+{
+    /** Performs a PHPUnit assertion that a generated Mermaid graph equals an expected result. */
+    public static function assertGraphEquals(string $expectedGraphString, Graph $actualGraph): void
+    {
+        Assert::assertSame(
+            expected: $expectedGraphString,
+            actual: $actualGraph->__toString(),
+            message: "The Mermaid graph did not match. See the actual generated graph at {$actualGraph->getLiveEditorUrl()}."
+        );
+    }
+
+    public static function assertStateConfigEquals(string $expectedGraphString, StateConfig $actualStateConfig): void
+    {
+        self::assertGraphEquals(
+            expectedGraphString: $expectedGraphString,
+            actualGraph: self::graphFromStateConfig($actualStateConfig),
+        );
+    }
+
+    public static function graphFromStateConfig(StateConfig $stateConfig): Graph
+    {
+        $graph = (new Graph(['abc_order' => true]))
+            ->addStyle('linkStyle default interpolate basis');
+
+        $possibleStateInstances = array_map(
+            static fn (string $stateClass): State => new $stateClass(),
+            $stateConfig->possibleStates(),
+        );
+
+        foreach ($possibleStateInstances as $state) {
+            $graph->addNode(new Node($state::name()));
+        }
+
+        foreach ($possibleStateInstances as $state) {
+            foreach ($stateConfig->possibleNextStates($state) as $possibleNextState) {
+                $sourceNode = $graph->getNode($state::name());
+                $targetNode = $graph->getNode($possibleNextState::name());
+
+                if ($sourceNode instanceof Node && $targetNode instanceof Node) {
+                    $transition = $stateConfig->transition($state::class, $possibleNextState::class);
+                    assert($transition !== null);
+
+                    $reflectionClass = new \ReflectionClass($transition);
+                    $transitionName = $reflectionClass->getName() === DefaultTransition::class
+                        ? ''
+                        : $reflectionClass->getShortName();
+
+                    $graph->addLink(new Link($sourceNode, $targetNode, $transitionName));
+                }
+            }
+        }
+
+        return $graph;
+    }
+}
diff --git a/tests/ModelStates/StateTest.php b/tests/ModelStates/StateTest.php
index 2238654..0686530 100644
--- a/tests/ModelStates/StateTest.php
+++ b/tests/ModelStates/StateTest.php
@@ -2,6 +2,7 @@
 
 namespace MLL\LaravelUtils\Tests\ModelStates;
 
+use App\ModelStates\ModelStates\ModelState;
 use App\ModelStates\ModelStates\StateA;
 use App\ModelStates\ModelStates\StateB;
 use App\ModelStates\ModelStates\StateC;
@@ -18,6 +19,7 @@
 use MLL\LaravelUtils\ModelStates\Exceptions\TransitionNotAllowed;
 use MLL\LaravelUtils\ModelStates\Exceptions\TransitionNotFound;
 use MLL\LaravelUtils\ModelStates\Exceptions\UnknownStateException;
+use MLL\LaravelUtils\ModelStates\MermaidStateConfigValidator;
 use MLL\LaravelUtils\ModelStates\TransitionDirection;
 use MLL\LaravelUtils\Tests\DBTestCase;
 
@@ -182,9 +184,8 @@ public function testUnknownStateThrowsExceptionsForRetrieval(): void
 
     public function testGenerateMermaidGraph(): void
     {
-        $model = new TestModel();
-
-        $workflowAsMermaidGraph = 'graph TB;
+        $workflowAsMermaidGraph = /** @lang Mermaid */ <<<'MERMAID'
+graph TB;
     FOO_BAR("FOO_BAR");
     STATE_A("STATE_A");
     STATE_C("STATE_C");
@@ -195,12 +196,9 @@ public function testGenerateMermaidGraph(): void
     STATE_A-->STATE_C;
     STATE_A-->STATE_D;
 
-linkStyle default interpolate basis;';
+linkStyle default interpolate basis;
+MERMAID;
 
-        self::assertSame(
-            $workflowAsMermaidGraph,
-            $model->generateMermaidGraphAsString(),
-            'Use https://mermaid.live/ for debugging.'
-        );
+        MermaidStateConfigValidator::assertStateConfigEquals($workflowAsMermaidGraph, ModelState::config());
     }
 }