diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index b33f771b9c..3d98de7755 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1551,18 +1551,6 @@ parameters:
 			count: 1
 			path: src/Type/Php/CompactFunctionReturnTypeExtension.php
 
-		-
-			rawMessage: 'Doing instanceof PHPStan\Type\Constant\ConstantStringType is error-prone and deprecated. Use Type::getConstantStrings() instead.'
-			identifier: phpstanApi.instanceofType
-			count: 1
-			path: src/Type/Php/DefineConstantTypeSpecifyingExtension.php
-
-		-
-			rawMessage: 'Doing instanceof PHPStan\Type\Constant\ConstantStringType is error-prone and deprecated. Use Type::getConstantStrings() instead.'
-			identifier: phpstanApi.instanceofType
-			count: 1
-			path: src/Type/Php/DefinedConstantTypeSpecifyingExtension.php
-
 		-
 			rawMessage: 'Doing instanceof PHPStan\Type\TypeWithClassName is error-prone and deprecated. Use Type::getObjectClassNames() or Type::getObjectClassReflections() instead.'
 			identifier: phpstanApi.instanceofType
diff --git a/src/Type/Php/DefineConstantTypeSpecifyingExtension.php b/src/Type/Php/DefineConstantTypeSpecifyingExtension.php
index 290f6fe437..711a334770 100644
--- a/src/Type/Php/DefineConstantTypeSpecifyingExtension.php
+++ b/src/Type/Php/DefineConstantTypeSpecifyingExtension.php
@@ -11,7 +11,6 @@
 use PHPStan\Analyser\TypeSpecifierContext;
 use PHPStan\DependencyInjection\AutowiredService;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FunctionTypeSpecifyingExtension;
 use function count;
 
@@ -45,23 +44,21 @@ public function specifyTypes(
 	): SpecifiedTypes
 	{
 		$args = $node->getArgs();
-		$constantName = $scope->getType($args[0]->value);
-		if (
-			!$constantName instanceof ConstantStringType
-			|| $constantName->getValue() === ''
-		) {
+		$constantNames = $scope->getType($args[0]->value)->getConstantStrings();
+
+		if (count($constantNames) !== 1 || $constantNames[0]->getValue() === '') {
 			return new SpecifiedTypes([], []);
 		}
 
 		$valueType = $scope->getType($args[1]->value);
 		$finalType = $scope->getConstantExplicitTypeFromConfig(
-			$constantName->getValue(),
+			$constantNames[0]->getValue(),
 			$valueType,
 		);
 
 		return $this->typeSpecifier->create(
 			new Node\Expr\ConstFetch(
-				new Node\Name\FullyQualified($constantName->getValue()),
+				new Node\Name\FullyQualified($constantNames[0]->getValue()),
 			),
 			$finalType,
 			TypeSpecifierContext::createTruthy(),
diff --git a/src/Type/Php/DefinedConstantTypeSpecifyingExtension.php b/src/Type/Php/DefinedConstantTypeSpecifyingExtension.php
index df0fe21f2b..e371fbbcdb 100644
--- a/src/Type/Php/DefinedConstantTypeSpecifyingExtension.php
+++ b/src/Type/Php/DefinedConstantTypeSpecifyingExtension.php
@@ -10,7 +10,6 @@
 use PHPStan\Analyser\TypeSpecifierContext;
 use PHPStan\DependencyInjection\AutowiredService;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FunctionTypeSpecifyingExtension;
 use PHPStan\Type\MixedType;
 use function count;
@@ -48,15 +47,14 @@ public function specifyTypes(
 		TypeSpecifierContext $context,
 	): SpecifiedTypes
 	{
-		$constantName = $scope->getType($node->getArgs()[0]->value);
-		if (
-			!$constantName instanceof ConstantStringType
-			|| $constantName->getValue() === ''
-		) {
+		$args = $node->getArgs();
+		$constantNames = $scope->getType($args[0]->value)->getConstantStrings();
+
+		if (count($constantNames) !== 1 || $constantNames[0]->getValue() === '') {
 			return new SpecifiedTypes([], []);
 		}
 
-		$expr = $this->constantHelper->createExprFromConstantName($constantName->getValue());
+		$expr = $this->constantHelper->createExprFromConstantName($constantNames[0]->getValue());
 		if ($expr === null) {
 			return new SpecifiedTypes([], []);
 		}