diff --git a/devTools/Dockerfile b/devTools/Dockerfile
index d213f3a19..96b46f548 100644
--- a/devTools/Dockerfile
+++ b/devTools/Dockerfile
@@ -35,7 +35,7 @@ RUN apk add --no-cache \
         git \
         zip
 
-COPY --from=composer:2.1 /usr/bin/composer /usr/bin/composer
+COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
 COPY memory-limit.ini xdebug.ini ${PHP_INI_DIR}/conf.d/
 
 RUN adduser -h /opt/infection -s /bin/bash -D infection
diff --git a/devTools/phpstan-src-baseline.neon b/devTools/phpstan-src-baseline.neon
index cf2c568b4..4cfab9fe2 100644
--- a/devTools/phpstan-src-baseline.neon
+++ b/devTools/phpstan-src-baseline.neon
@@ -371,17 +371,12 @@ parameters:
 			path: ../src/Mutator/MutatorResolver.php
 
 		-
-			message: "#^Parameter &\\$mutators by\\-ref type of method Infection\\\\Mutator\\\\MutatorResolver\\:\\:registerFromClass\\(\\) expects array\\<string, array\\<string\\>\\>, array\\<string, array\\<array\\<string\\>\\|string\\>\\> given\\.$#"
+			message: "#^Parameter &\\$mutators by\\-ref type of method Infection\\\\Mutator\\\\MutatorResolver\\:\\:registerFromClass\\(\\) expects array\\<string, array\\<string, string\\>\\>, array\\<string, array\\<string, array\\<string\\>\\|string\\>\\> given\\.$#"
 			count: 1
 			path: ../src/Mutator/MutatorResolver.php
 
 		-
-			message: "#^Parameter &\\$mutators by\\-ref type of method Infection\\\\Mutator\\\\MutatorResolver\\:\\:registerFromClass\\(\\) expects array\\<string, array\\<string\\>\\>, array\\<string, array\\> given\\.$#"
-			count: 1
-			path: ../src/Mutator/MutatorResolver.php
-
-		-
-			message: "#^Parameter &\\$mutators by\\-ref type of method Infection\\\\Mutator\\\\MutatorResolver\\:\\:registerFromName\\(\\) expects array\\<string, array\\<string, string\\>\\>, array\\<string, array\\<string\\>\\> given\\.$#"
+			message: "#^Parameter &\\$mutators by\\-ref type of method Infection\\\\Mutator\\\\MutatorResolver\\:\\:registerFromClass\\(\\) expects array\\<string, array\\<string, string\\>\\>, array\\<string, array\\> given\\.$#"
 			count: 1
 			path: ../src/Mutator/MutatorResolver.php
 
diff --git a/devTools/phpstan-src.neon b/devTools/phpstan-src.neon
index bf63e83cb..af3414d5a 100644
--- a/devTools/phpstan-src.neon
+++ b/devTools/phpstan-src.neon
@@ -53,11 +53,6 @@ parameters:
             count: 1
             path: ../src/Logger/Html/StrykerHtmlReportBuilder.php
 
-        -
-            message: "#^PHPDoc tag @var with type Infection\\\\Mutator\\\\Mutator\\<PhpParser\\\\NodeAbstract\\> is not subtype of native type 'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Assignment'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\AssignmentEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\BitwiseAnd'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\BitwiseNot'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\BitwiseOr'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\BitwiseXor'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Decrement'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\DivEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Division'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Exponentiation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Increment'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Minus'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\MinusEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\ModEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Modulus'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\MulEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Multiplication'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\Plus'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\PlusEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\PowEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\RoundingFamily'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\ShiftLeft'\\|'Infection\\\\\\\\Mutator\\\\\\\\Arithmetic\\\\\\\\ShiftRight'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\ArrayItem'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\EqualIdentical'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\FalseValue'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\IdenticalEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\InstanceOf_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalAnd'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalAndAllSubExprNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalAndNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalAndSingleSubExprNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalLowerAnd'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalLowerOr'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalNot'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalOr'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalOrAllSubExprNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalOrNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\LogicalOrSingleSubExprNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\NotEqualNotIdentical'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\NotIdenticalNotEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\TrueValue'\\|'Infection\\\\\\\\Mutator\\\\\\\\Boolean\\\\\\\\Yield_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastArray'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastBool'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastFloat'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastInt'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastObject'\\|'Infection\\\\\\\\Mutator\\\\\\\\Cast\\\\\\\\CastString'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalBoundary\\\\\\\\GreaterThan'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalBoundary\\\\\\\\GreaterThanOrEqualTo'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalBoundary\\\\\\\\LessThan'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalBoundary\\\\\\\\LessThanOrEqualTo'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\Equal'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\GreaterThanNegotiation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\GreaterThanOrEqualToNegotiation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\Identical'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\LessThanNegotiation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\LessThanOrEqualToNegotiation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\NotEqual'\\|'Infection\\\\\\\\Mutator\\\\\\\\ConditionalNegotiation\\\\\\\\NotIdentical'\\|'Infection\\\\\\\\Mutator\\\\\\\\Extensions\\\\\\\\BCMath'\\|'Infection\\\\\\\\Mutator\\\\\\\\Extensions\\\\\\\\MBString'\\|'Infection\\\\\\\\Mutator\\\\\\\\FunctionSignature\\\\\\\\ProtectedVisibility'\\|'Infection\\\\\\\\Mutator\\\\\\\\FunctionSignature\\\\\\\\PublicVisibility'\\|'Infection\\\\\\\\Mutator\\\\\\\\Loop\\\\\\\\DoWhile'\\|'Infection\\\\\\\\Mutator\\\\\\\\Loop\\\\\\\\For_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Loop\\\\\\\\Foreach_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Loop\\\\\\\\While_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Number\\\\\\\\DecrementInteger'\\|'Infection\\\\\\\\Mutator\\\\\\\\Number\\\\\\\\IncrementInteger'\\|'Infection\\\\\\\\Mutator\\\\\\\\Number\\\\\\\\OneZeroFloat'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\AssignCoalesce'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Break_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Catch_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Coalesce'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Concat'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Continue_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\ElseIfNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Finally_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\IfNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\NullSafeMethodCall'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\NullSafePropertyCall'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\SpreadAssignment'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\SpreadOneItem'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\SpreadRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Ternary'\\|'Infection\\\\\\\\Mutator\\\\\\\\Operator\\\\\\\\Throw_'\\|'Infection\\\\\\\\Mutator\\\\\\\\Regex\\\\\\\\PregMatchMatches'\\|'Infection\\\\\\\\Mutator\\\\\\\\Regex\\\\\\\\PregMatchRemoveCaret'\\|'Infection\\\\\\\\Mutator\\\\\\\\Regex\\\\\\\\PregMatchRemoveDollar'\\|'Infection\\\\\\\\Mutator\\\\\\\\Regex\\\\\\\\PregMatchRemoveFlags'\\|'Infection\\\\\\\\Mutator\\\\\\\\Regex\\\\\\\\PregQuote'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\ArrayItemRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\CatchBlockRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\CloneRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\ConcatOperandRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\FunctionCallRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\MatchArmRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\MethodCallRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\Removal\\\\\\\\SharedCaseRemoval'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\ArrayOneItem'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\FloatNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\FunctionCall'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\IntegerNegation'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\NewObject'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\This'\\|'Infection\\\\\\\\Mutator\\\\\\\\ReturnValue\\\\\\\\YieldValue'\\|'Infection\\\\\\\\Mutator\\\\\\\\Sort\\\\\\\\Spaceship'\\|'Infection\\\\\\\\Mutator\\\\\\\\SyntaxError'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayChangeKeyCase'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayChunk'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayColumn'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayCombine'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayDiff'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayDiffAssoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayDiffKey'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayDiffUassoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayDiffUkey'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayFilter'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayFlip'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayIntersect'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayIntersectAssoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayIntersectKey'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayIntersectUassoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayIntersectUkey'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayKeys'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayMap'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayMerge'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayMergeRecursive'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayPad'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayReduce'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayReplace'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayReplaceRecursive'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayReverse'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArraySlice'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArraySplice'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUdiff'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUdiffAssoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUdiffUassoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUintersect'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUintersectAssoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUintersectUassoc'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayUnique'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapArrayValues'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapFinally'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapLcFirst'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapLtrim'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapRtrim'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrIreplace'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrRepeat'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrReplace'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrRev'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrShuffle'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrToLower'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapStrToUpper'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapSubstr'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapTrim'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapUcFirst'\\|'Infection\\\\\\\\Mutator\\\\\\\\Unwrap\\\\\\\\UnwrapUcWords'\\.$#"
-            count: 1
-            path: ../src/Logger/Html/StrykerHtmlReportBuilder.php
-
         -
             message: "#^Generator expects value type list\\<PhpParser\\\\Node\\\\Stmt\\>, array\\<PhpParser\\\\Node\\\\Stmt\\> given\\.$#"
             count: 1
diff --git a/scoper.inc.php b/scoper.inc.php
index b19709078..73a198274 100644
--- a/scoper.inc.php
+++ b/scoper.inc.php
@@ -35,6 +35,11 @@
 
 return [
     'prefix' => 'Infected',
+    'exclude-classes' => [
+        'Infection\Mutator\Definition',
+        'Infection\Mutator\Mutator',
+        'Infection\Mutator\MutatorCategory',
+    ],
     'exclude-constants' => [
         // Symfony global constants
         '/^SYMFONY\_[\p{L}_]+$/',
diff --git a/src/Logger/Html/StrykerHtmlReportBuilder.php b/src/Logger/Html/StrykerHtmlReportBuilder.php
index c1c871092..5f724aa4d 100644
--- a/src/Logger/Html/StrykerHtmlReportBuilder.php
+++ b/src/Logger/Html/StrykerHtmlReportBuilder.php
@@ -64,6 +64,7 @@
 use function Safe\file_get_contents;
 use function Safe\preg_match;
 use function Safe\preg_split;
+use function sprintf;
 use function str_starts_with;
 use function strlen;
 use function substr;
diff --git a/src/Mutant/MutantExecutionResult.php b/src/Mutant/MutantExecutionResult.php
index d2b54eef8..b2ab593da 100644
--- a/src/Mutant/MutantExecutionResult.php
+++ b/src/Mutant/MutantExecutionResult.php
@@ -52,7 +52,6 @@ class MutantExecutionResult
 {
     private readonly string $detectionStatus;
     private readonly string $mutatorClass;
-    private readonly string $mutatorName;
 
     /**
      * @param Deferred<string> $mutantDiff
@@ -67,7 +66,7 @@ public function __construct(
         private readonly Deferred $mutantDiff,
         private readonly string $mutantHash,
         string $mutatorClass,
-        string $mutatorName,
+        private readonly string $mutatorName,
         private readonly string $originalFilePath,
         private readonly int $originalStartingLine,
         private readonly int $originalEndingLine,
@@ -82,7 +81,6 @@ public function __construct(
 
         $this->detectionStatus = $detectionStatus;
         $this->mutatorClass = $mutatorClass;
-        $this->mutatorName = $mutatorName;
     }
 
     public static function createFromNonCoveredMutant(Mutant $mutant): self
diff --git a/src/Mutation/Mutation.php b/src/Mutation/Mutation.php
index 9c36586de..cb516a9b3 100644
--- a/src/Mutation/Mutation.php
+++ b/src/Mutation/Mutation.php
@@ -44,6 +44,7 @@
 use Infection\TestFramework\Coverage\JUnit\JUnitTestCaseTimeAdder;
 use function md5;
 use PhpParser\Node;
+use function sprintf;
 use Webmozart\Assert\Assert;
 
 /**
@@ -52,8 +53,7 @@
  */
 class Mutation
 {
-    private string $mutatorClass;
-    private readonly string $mutatorName;
+    private readonly string $mutatorClass;
     /** @var array<string|int|float> */
     private readonly array $attributes;
     private readonly bool $coveredByTests;
@@ -70,7 +70,7 @@ public function __construct(
         private readonly string $originalFilePath,
         private readonly array $originalFileAst,
         string $mutatorClass,
-        string $mutatorName,
+        private readonly string $mutatorName,
         array $attributes,
         private readonly string $mutatedNodeClass,
         private readonly MutatedNode $mutatedNode,
@@ -83,7 +83,6 @@ public function __construct(
             Assert::keyExists($attributes, $key);
         }
         $this->mutatorClass = $mutatorClass;
-        $this->mutatorName = $mutatorName;
         $this->attributes = array_intersect_key($attributes, array_flip(MutationAttributeKeys::ALL));
         $this->coveredByTests = $tests !== [];
     }
diff --git a/src/Mutator/Definition.php b/src/Mutator/Definition.php
index ff5be03ea..8fee0e033 100644
--- a/src/Mutator/Definition.php
+++ b/src/Mutator/Definition.php
@@ -37,9 +37,6 @@
 
 use Webmozart\Assert\Assert;
 
-/**
- * @internal
- */
 final class Definition
 {
     private readonly string $category;
diff --git a/src/Mutator/Mutator.php b/src/Mutator/Mutator.php
index f4c9ca97f..50206326c 100644
--- a/src/Mutator/Mutator.php
+++ b/src/Mutator/Mutator.php
@@ -38,7 +38,6 @@
 use PhpParser\Node;
 
 /**
- * @internal
  * @template TNode of Node
  */
 interface Mutator
diff --git a/src/Mutator/MutatorCategory.php b/src/Mutator/MutatorCategory.php
index b9daa2dfb..49950393c 100644
--- a/src/Mutator/MutatorCategory.php
+++ b/src/Mutator/MutatorCategory.php
@@ -37,9 +37,6 @@
 
 use Infection\CannotBeInstantiated;
 
-/**
- * @internal
- */
 final class MutatorCategory
 {
     use CannotBeInstantiated;
diff --git a/src/Mutator/MutatorFactory.php b/src/Mutator/MutatorFactory.php
index 9712885df..0290c84e2 100644
--- a/src/Mutator/MutatorFactory.php
+++ b/src/Mutator/MutatorFactory.php
@@ -35,7 +35,6 @@
 
 namespace Infection\Mutator;
 
-use function array_flip;
 use function end;
 use function explode;
 use function is_a;
diff --git a/src/Mutator/MutatorResolver.php b/src/Mutator/MutatorResolver.php
index f98958c40..39e221847 100644
--- a/src/Mutator/MutatorResolver.php
+++ b/src/Mutator/MutatorResolver.php
@@ -42,6 +42,7 @@
 use function class_exists;
 use function in_array;
 use InvalidArgumentException;
+use function is_subclass_of;
 use function sprintf;
 use stdClass;
 
@@ -116,7 +117,7 @@ public function resolve(array $mutatorSettings): array
                 self::registerFromClass(
                     $mutatorOrProfile,
                     $resolvedSettings,
-                    $mutators
+                    $mutators,
                 );
 
                 continue;
diff --git a/tests/add_new_e2e b/tests/add_new_e2e
index 3bd164ea1..3bdd3c4d5 100755
--- a/tests/add_new_e2e
+++ b/tests/add_new_e2e
@@ -17,7 +17,7 @@ cp -r Example_Test/src "$dirname"/src
 cp -r Example_Test/tests $dirname/tests
 cp  Example_Test/composer.json $dirname/composer.json
 cp  Example_Test/expected-output.txt $dirname/expected-output.txt
-cp  Example_Test/infection.json $dirname/infection.json
+cp  Example_Test/infection.json5 $dirname/infection.json5
 cp  Example_Test/phpunit.xml $dirname/phpunit.xml
 cp  Example_Test/README.md $dirname/README.md
 
diff --git a/tests/e2e/Custom_Mutator/README.md b/tests/e2e/Custom_Mutator/README.md
new file mode 100644
index 000000000..baf513e33
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/README.md
@@ -0,0 +1,9 @@
+# Title
+
+* Link to github ticket if relevant
+
+## Summary
+Short summary of the ticket
+
+## Full Ticket
+Full github ticket
\ No newline at end of file
diff --git a/tests/e2e/Custom_Mutator/composer.json b/tests/e2e/Custom_Mutator/composer.json
new file mode 100644
index 000000000..cfd19925a
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/composer.json
@@ -0,0 +1,15 @@
+{
+    "require-dev": {
+        "phpunit/phpunit": "^9.5.5"
+    },
+    "autoload": {
+        "psr-4": {
+            "Custom_Mutator\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Custom_Mutator\\Test\\": "tests/"
+        }
+    }
+}
diff --git a/tests/e2e/Custom_Mutator/expected-output.txt b/tests/e2e/Custom_Mutator/expected-output.txt
new file mode 100644
index 000000000..e4dbc2085
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/expected-output.txt
@@ -0,0 +1,10 @@
+Total: 1
+
+Killed: 1
+Errored: 0
+Syntax Errors: 0
+Escaped: 0
+Timed Out: 0
+Skipped: 0
+Ignored: 0
+Not Covered: 0
diff --git a/tests/e2e/Custom_Mutator/infection.json5 b/tests/e2e/Custom_Mutator/infection.json5
new file mode 100644
index 000000000..b21ef6a1e
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/infection.json5
@@ -0,0 +1,20 @@
+{
+    "$schema": "../../../resources/schema.json",
+    "timeout": 25,
+    "source": {
+        "directories": [
+            "src"
+        ],
+        "excludes": [
+            "Mutator/CustomMutator.php"
+        ]
+    },
+    "mutators": {
+        "@default": false,
+        "Custom_Mutator\\Mutator\\CustomMutator": true
+    },
+    "logs": {
+        "summary": "infection.log"
+    },
+    "tmpDir": "."
+}
diff --git a/tests/e2e/Custom_Mutator/phpunit.xml b/tests/e2e/Custom_Mutator/phpunit.xml
new file mode 100644
index 000000000..c11ab317a
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/phpunit.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
+         bootstrap="./vendor/autoload.php"
+         colors="true"
+>
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory>./tests/</directory>
+        </testsuite>
+    </testsuites>
+
+    <coverage>
+        <include>
+            <directory>./src/</directory>
+        </include>
+    </coverage>
+</phpunit>
diff --git a/tests/e2e/Custom_Mutator/src/Mutator/CustomMutator.php b/tests/e2e/Custom_Mutator/src/Mutator/CustomMutator.php
new file mode 100644
index 000000000..39ed5668d
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/src/Mutator/CustomMutator.php
@@ -0,0 +1,95 @@
+<?php
+/**
+ * This code is licensed under the BSD 3-Clause License.
+ *
+ * Copyright (c) 2017, Maks Rafalko
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+declare(strict_types=1);
+
+namespace Custom_Mutator\Mutator;
+
+use Infection\Mutator\Definition;
+use Infection\Mutator\Mutator;
+use Infection\Mutator\MutatorCategory;
+use PhpParser\Node;
+use function end;
+use function explode;
+
+/**
+ * @implements Mutator<Node\Expr\BinaryOp\Plus>
+ */
+final class CustomMutator implements Mutator
+{
+    public function getName(): string
+    {
+        $parts = explode('\\', self::class);
+
+        return end($parts);
+    }
+
+    public static function getDefinition(): ?Definition
+    {
+        return new Definition(
+            <<<'TXT'
+                Replaces an addition operator (`+`) with a subtraction operator (`-`).
+                TXT
+            ,
+            MutatorCategory::ORTHOGONAL_REPLACEMENT,
+            null,
+            <<<'DIFF'
+                - $a = $b + $c;
+                + $a = $b - $c;
+                DIFF,
+        );
+    }
+
+    /**
+     * @psalm-mutation-free
+     *
+     * @return iterable<Node\Expr\BinaryOp\Minus>
+     */
+    public function mutate(Node $node): iterable
+    {
+        yield new Node\Expr\BinaryOp\Minus($node->left, $node->right, $node->getAttributes());
+    }
+
+    public function canMutate(Node $node): bool
+    {
+        if (!$node instanceof Node\Expr\BinaryOp\Plus) {
+            return false;
+        }
+
+        if ($node->left instanceof Node\Expr\Array_ || $node->right instanceof Node\Expr\Array_) {
+            return false;
+        }
+
+        return true;
+    }
+}
diff --git a/tests/e2e/Custom_Mutator/src/SourceClass.php b/tests/e2e/Custom_Mutator/src/SourceClass.php
new file mode 100644
index 000000000..37259f0fc
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/src/SourceClass.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace Custom_Mutator;
+
+class SourceClass
+{
+    public function hello(): string
+    {
+        $a = 1;
+        $b = $a + 2;
+
+        return 'hello';
+    }
+}
diff --git a/tests/e2e/Custom_Mutator/tests/SourceClassTest.php b/tests/e2e/Custom_Mutator/tests/SourceClassTest.php
new file mode 100644
index 000000000..a9aeace7a
--- /dev/null
+++ b/tests/e2e/Custom_Mutator/tests/SourceClassTest.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Custom_Mutator\Test;
+
+use Custom_Mutator\SourceClass;
+use PHPUnit\Framework\TestCase;
+
+class SourceClassTest extends TestCase
+{
+    public function test_hello()
+    {
+        $sourceClass = new SourceClass();
+        $this->assertSame('hello', $sourceClass->hello());
+    }
+}
diff --git a/tests/e2e/Example_Test/infection.json b/tests/e2e/Example_Test/infection.json5
similarity index 100%
rename from tests/e2e/Example_Test/infection.json
rename to tests/e2e/Example_Test/infection.json5
diff --git a/tests/phpunit/AutoReview/ProjectCode/ProjectCodeProvider.php b/tests/phpunit/AutoReview/ProjectCode/ProjectCodeProvider.php
index d863e98cd..b3f56f59f 100644
--- a/tests/phpunit/AutoReview/ProjectCode/ProjectCodeProvider.php
+++ b/tests/phpunit/AutoReview/ProjectCode/ProjectCodeProvider.php
@@ -64,6 +64,9 @@
 use Infection\Metrics\MetricsCalculator;
 use Infection\Mutant\DetectionStatus;
 use Infection\Mutation\MutationAttributeKeys;
+use Infection\Mutator\Definition;
+use Infection\Mutator\Mutator;
+use Infection\Mutator\MutatorCategory;
 use Infection\Mutator\NodeMutationGenerator;
 use Infection\Process\Runner\IndexedProcessBearer;
 use Infection\Process\ShellCommandLineExecutor;
@@ -141,6 +144,9 @@ final class ProjectCodeProvider
         SchemaConfigurationFactory::class,
         SchemaConfigurationFileLoader::class,
         SchemaValidator::class,
+        Mutator::class,
+        Definition::class,
+        MutatorCategory::class,
     ];
 
     /**
diff --git a/tests/phpunit/PhpParser/Visitor/MutatorVisitorTest.php b/tests/phpunit/PhpParser/Visitor/MutatorVisitorTest.php
index dbbf7dccd..79cf009e1 100644
--- a/tests/phpunit/PhpParser/Visitor/MutatorVisitorTest.php
+++ b/tests/phpunit/PhpParser/Visitor/MutatorVisitorTest.php
@@ -109,9 +109,9 @@ public function hello(): string
                 'path/to/file',
                 $nodes,
                 PublicVisibility::class,
-                    MutatorName::getName(PublicVisibility::class),
-                    [
-                        'startTokenPos' => 28,
+                MutatorName::getName(PublicVisibility::class),
+                [
+                    'startTokenPos' => 28,
                     'endTokenPos' => 46,
                     'startLine' => -1,
                     'endLine' => -1,
@@ -160,9 +160,9 @@ public function hello(): string
                 'path/to/file',
                 $nodes,
                 PublicVisibility::class,
-                    MutatorName::getName(PublicVisibility::class),
-                    [
-                        'startTokenPos' => 28,
+                MutatorName::getName(PublicVisibility::class),
+                [
+                    'startTokenPos' => 28,
                     'endTokenPos' => 46,
                     'startLine' => -1,
                     'endLine' => -1,
@@ -213,19 +213,19 @@ public function bye(): string
                 'path/to/file',
                 $nodes,
                 PublicVisibility::class,
-                    MutatorName::getName(PublicVisibility::class),
-                    [
-                        'startTokenPos' => 29,
-                        'endTokenPos' => 50,
-                        'startLine' => -1,
-                        'endLine' => -1,
-                        'startFilePos' => -1,
-                        'endFilePos' => -1,
-                    ],
-                    ClassMethod::class,
-                    MutatedNode::wrap(new Nop()),
-                    0,
-                    [],
+                MutatorName::getName(PublicVisibility::class),
+                [
+                    'startTokenPos' => 29,
+                    'endTokenPos' => 50,
+                    'startLine' => -1,
+                    'endLine' => -1,
+                    'startFilePos' => -1,
+                    'endFilePos' => -1,
+                ],
+                ClassMethod::class,
+                MutatedNode::wrap(new Nop()),
+                0,
+                [],
             ),
         ])();