diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index b22d651f99..f09e4a9bb6 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -4767,18 +4767,29 @@ private function processArgs(
 				}
 
 				$argValue = $arg->value;
-				if ($argValue instanceof Variable && is_string($argValue->name)) {
-					if ($argValue->name !== 'this') {
-						$paramOutType = $this->getParameterOutExtensionsType($callLike, $calleeReflection, $currentParameter, $scope);
-						if ($paramOutType !== null) {
-							$byRefType = $paramOutType;
-						}
-
-						$nodeCallback(new VariableAssignNode($argValue, new TypeExpr($byRefType), false), $scope);
-						$scope = $scope->assignVariable($argValue->name, $byRefType, new MixedType());
+				if (!$argValue instanceof Variable || $argValue->name !== 'this') {
+					$paramOutType = $this->getParameterOutExtensionsType($callLike, $calleeReflection, $currentParameter, $scope);
+					if ($paramOutType !== null) {
+						$byRefType = $paramOutType;
 					}
-				} else {
-					$scope = $scope->invalidateExpression($argValue);
+
+					$result = $this->processAssignVar(
+						$scope,
+						$stmt,
+						$argValue,
+						new TypeExpr($byRefType),
+						static function (Node $node, Scope $scope) use ($nodeCallback): void {
+							if (!$node instanceof PropertyAssignNode && !$node instanceof VariableAssignNode) {
+								return;
+							}
+
+							$nodeCallback($node, $scope);
+						},
+						$context,
+						static fn (MutatingScope $scope): ExpressionResult => new ExpressionResult($scope, false, [], []),
+						true,
+					);
+					$scope = $result->getScope();
 				}
 			} elseif ($calleeReflection !== null && $calleeReflection->hasSideEffects()->yes()) {
 				$argType = $scope->getType($arg->value);
diff --git a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
index 09f34d1d40..33551884d8 100644
--- a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
+++ b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
@@ -107,6 +107,21 @@ public function testTypesAssignedToProperties(): void
 				'Property PropertiesAssignedTypes\AppendToArrayAccess::$collection2 (ArrayAccess<int, string>&Countable) does not accept Countable.',
 				376,
 			],
+			[
+				'Property PropertiesAssignedTypes\ParamOutAssign::$foo (list<string>) does not accept string.',
+				400,
+				'string is not a list.',
+			],
+			[
+				'Property PropertiesAssignedTypes\ParamOutAssign::$foo2 (list<list<string>>) does not accept string.',
+				410,
+				'string is not a list.',
+			],
+			[
+				'Property PropertiesAssignedTypes\ParamOutAssign::$foo2 (list<list<string>>) does not accept non-empty-list<list<string>|string>.',
+				415,
+				'list<string>|string might not be a list.',
+			],
 		]);
 	}
 
diff --git a/tests/PHPStan/Rules/Properties/data/properties-assigned-types.php b/tests/PHPStan/Rules/Properties/data/properties-assigned-types.php
index 3686d4d244..14b3ad66e4 100644
--- a/tests/PHPStan/Rules/Properties/data/properties-assigned-types.php
+++ b/tests/PHPStan/Rules/Properties/data/properties-assigned-types.php
@@ -376,3 +376,48 @@ public function foo(): void
 		$this->collection2[] = 2;
 	}
 }
+
+class ParamOutAssign
+{
+
+	/** @var list<string> */
+	private $foo;
+
+	/** @var list<list<string>> */
+	private $foo2;
+
+	/**
+	 * @param mixed $a
+	 * @param-out string $a
+	 */
+	public function paramOut(&$a): void
+	{
+
+	}
+
+	public function doFoo(): void
+	{
+		$this->paramOut($this->foo);
+	}
+
+	public function doFoo2(): void
+	{
+		$this->paramOut($this->foo[0]);
+	}
+
+	public function doBar(): void
+	{
+		$this->paramOut($this->foo2);
+	}
+
+	public function doBar2(): void
+	{
+		$this->paramOut($this->foo2[0]);
+	}
+
+	public function doBar3(): void
+	{
+		$this->paramOut($this->foo2[0][0]);
+	}
+
+}
diff --git a/tests/PHPStan/Rules/TooWideTypehints/TooWidePropertyTypeRuleTest.php b/tests/PHPStan/Rules/TooWideTypehints/TooWidePropertyTypeRuleTest.php
index f512d22fc7..1171abd564 100644
--- a/tests/PHPStan/Rules/TooWideTypehints/TooWidePropertyTypeRuleTest.php
+++ b/tests/PHPStan/Rules/TooWideTypehints/TooWidePropertyTypeRuleTest.php
@@ -56,4 +56,9 @@ public function testRule(): void
 		]);
 	}
 
+	public function testBug11667(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-11667.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/TooWideTypehints/data/bug-11667.php b/tests/PHPStan/Rules/TooWideTypehints/data/bug-11667.php
new file mode 100644
index 0000000000..09bd5a8919
--- /dev/null
+++ b/tests/PHPStan/Rules/TooWideTypehints/data/bug-11667.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Bug11667;
+
+final class HelloWorld {
+	/** @var list<string>|null */
+	private $matches = null;
+
+	public function match(string $string): void {
+		preg_match('/Hello (\w+)/', $string, $this->matches);
+	}
+
+	/** @return list<string>|null */
+	public function get(): ?array {
+		return $this->matches;
+	}
+}
+
+final class HelloWorld2 {
+	/** @var list<string>|null */
+	private $matches = null;
+
+	public function match(string $string): void {
+		$this->paramOut($this->matches);
+	}
+
+	/**
+	 * @param mixed $a
+	 * @param-out list<string> $a
+	 */
+	public function paramOut(&$a): void
+	{
+
+	}
+
+	/** @return list<string>|null */
+	public function get(): ?array {
+		return $this->matches;
+	}
+}