diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index b85f94a6b81..2a607baa993 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -786,6 +786,18 @@ public function processExprNode(
 					return $storedResult;
 				}
 
+				// re-anchoring drops what the node did to the scope (an assignment
+				// inside a closure body an extension prices on demand) - such a
+				// node is re-processed on the asking scope instead
+				if (
+					!$consume
+					&& $storedResult->getScope() !== $storedResult->getBeforeScope()
+					&& !$expr instanceof Expr\Closure
+					&& !$expr instanceof Expr\ArrowFunction
+				) {
+					return $this->processExprNodeInternal($stmt, $expr, $scope, $storage, $nodeCallback, $context);
+				}
+
 				$reanchored = $storedResult->atAskPosition($scope);
 				if ($consume) {
 					// the re-anchored view IS this walk's result for the node
diff --git a/tests/PHPStan/Analyser/nsrt/bug-15491.php b/tests/PHPStan/Analyser/nsrt/bug-15491.php
new file mode 100644
index 00000000000..c38a17992bc
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-15491.php
@@ -0,0 +1,162 @@
+<?php declare(strict_types = 1);
+
+namespace Bug15491;
+
+use function PHPStan\Testing\assertType;
+
+function idFromAlias(string $alias): ?string
+{
+	return strpos($alias, '.') !== false ? md5($alias) : null;
+}
+
+/**
+ * @param array<string, mixed> $data
+ * @return array<string, mixed>
+ */
+function withCoalesce(array $data): array
+{
+	$data['ids'] = array_filter(
+		array_map(
+			function (string $alias): ?string {
+				$id = idFromAlias($alias);
+				if ($id === null) {
+					echo 'invalid';
+				}
+				return $id;
+			},
+			explode('|', (string) ($data['options'] ?? ''))
+		)
+	);
+	assertType('array<int<0, max>, non-falsy-string>', $data['ids']);
+
+	return $data;
+}
+
+/**
+ * @template T
+ * @param T $x
+ * @return T
+ */
+function identity($x)
+{
+	return $x;
+}
+
+/**
+ * @param mixed $x
+ * @return list<string>
+ */
+function strings($x): array
+{
+	return [];
+}
+
+/** @param array<string, mixed> $data */
+function assignOp(array $data): void
+{
+	$x = identity(array_map(
+		function (string $alias): int {
+			$i = 0;
+			$i += strlen($alias);
+			if ($i === 0) {
+				echo 'empty';
+			}
+			return $i;
+		},
+		strings($data['options'] ?? '')
+	));
+	assertType('list<int<0, max>>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function coalesceAssign(array $data): void
+{
+	$x = identity(array_map(
+		function (string $alias): ?string {
+			$id = null;
+			$id ??= idFromAlias($alias);
+			if ($id === null) {
+				echo 'invalid';
+			}
+			return $id;
+		},
+		strings($data['options'] ?? '')
+	));
+	assertType('list<string|null>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function increment(array $data): void
+{
+	$x = identity(array_map(
+		function (string $alias): int {
+			$i = 0;
+			$i++;
+			if ($i === 0) {
+				echo 'never';
+			}
+			return $i;
+		},
+		strings($data['options'] ?? '')
+	));
+	assertType('list<1>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function byRefOutParameter(array $data): void
+{
+	$x = identity(array_map(
+		function (string $alias): ?string {
+			$m = null;
+			preg_match('/a/', $alias, $m);
+			if ($m === null) {
+				echo 'never';
+			}
+			return $m[0] ?? null;
+		},
+		strings($data['options'] ?? '')
+	));
+	assertType('list<non-empty-string|null>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function listAssign(array $data): void
+{
+	$x = identity(array_map(
+		function (string $alias): ?string {
+			[$id] = [idFromAlias($alias)];
+			if ($id === null) {
+				echo 'invalid';
+			}
+			return $id;
+		},
+		strings($data['options'] ?? '')
+	));
+	assertType('list<string|null>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function arrowFunction(array $data): void
+{
+	$x = identity(array_map(
+		fn (string $alias): ?string => ($id = idFromAlias($alias)) === null ? $id : $id,
+		strings($data['options'] ?? '')
+	));
+	assertType('list<string|null>', $x);
+}
+
+/** @param array<string, mixed> $data */
+function arrayFilterCallback(array $data): void
+{
+	$x = identity(array_filter(
+		strings($data['options'] ?? ''),
+		function (string $alias): bool {
+			$id = idFromAlias($alias);
+			if ($id === null) {
+				echo 'invalid';
+			}
+			return $id !== null;
+		}
+	));
+	assertType('array<int<0, max>, string>', $x);
+}
diff --git a/tests/PHPStan/Rules/Functions/ArrayFilterRuleTest.php b/tests/PHPStan/Rules/Functions/ArrayFilterRuleTest.php
index 96be9603a85..10f5dbea47b 100644
--- a/tests/PHPStan/Rules/Functions/ArrayFilterRuleTest.php
+++ b/tests/PHPStan/Rules/Functions/ArrayFilterRuleTest.php
@@ -99,4 +99,9 @@ public function testBug2065WithoutPhpDocTypesAsCertain(): void
 		$this->analyse([__DIR__ . '/data/bug-array-filter.php'], []);
 	}
 
+	public function testBug15491(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15491.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Functions/data/bug-15491.php b/tests/PHPStan/Rules/Functions/data/bug-15491.php
new file mode 100644
index 00000000000..5a7818e0a61
--- /dev/null
+++ b/tests/PHPStan/Rules/Functions/data/bug-15491.php
@@ -0,0 +1,71 @@
+<?php declare(strict_types = 1);
+
+namespace Bug15491Rule;
+
+function idFromAlias(string $alias): ?string
+{
+	return strpos($alias, '.') !== false ? md5($alias) : null;
+}
+
+/**
+ * @param array<string, mixed> $data
+ * @return array<string, mixed>
+ */
+function withCoalesce(array $data): array
+{
+	$data['ids'] = array_filter(
+		array_map(
+			function (string $alias): ?string {
+				$id = idFromAlias($alias);
+				if ($id === null) {
+					echo 'invalid';
+				}
+				return $id;
+			},
+			explode('|', (string) ($data['options'] ?? ''))
+		)
+	);
+
+	return $data;
+}
+
+/**
+ * @param array<string, mixed> $data
+ * @return array<string, mixed>
+ */
+function withoutCoalesce(array $data): array
+{
+	$data['ids'] = array_filter(
+		array_map(
+			function (string $alias): ?string {
+				$id = idFromAlias($alias);
+				if ($id === null) {
+					echo 'invalid';
+				}
+				return $id;
+			},
+			explode('|', (string) $data['options'])
+		)
+	);
+
+	return $data;
+}
+
+/**
+ * @param array<string, mixed> $data
+ * @return array<string, mixed>
+ */
+function withoutIf(array $data): array
+{
+	$data['ids'] = array_filter(
+		array_map(
+			function (string $alias): ?string {
+				$id = idFromAlias($alias);
+				return $id;
+			},
+			explode('|', (string) ($data['options'] ?? ''))
+		)
+	);
+
+	return $data;
+}
diff --git a/turbo-ext/src/NodeScopeResolver.cpp b/turbo-ext/src/NodeScopeResolver.cpp
index b2d0b6b4a62..9847711096d 100644
--- a/turbo-ext/src/NodeScopeResolver.cpp
+++ b/turbo-ext/src/NodeScopeResolver.cpp
@@ -1963,6 +1963,20 @@ class NodeScopeResolver
 					if (UNEXPECTED(beforeScope.isUndef())) return zv::Val();
 					if (beforeScope.ref().isObject() && Z_OBJ_P(beforeScope.raw()) == Z_OBJ_P(scope)) return storedResult;
 
+					// re-anchoring drops what the node did to the scope - such a
+					// node is re-processed on the asking scope instead
+					if (!consume) {
+						zv::Val afterScope = expressionResultScope(storedResult.raw());
+						if (UNEXPECTED(afterScope.isUndef())) return zv::Val();
+						bool sameScope = afterScope.ref().isObject() && beforeScope.ref().isObject() && Z_OBJ_P(afterScope.raw()) == Z_OBJ_P(beforeScope.raw());
+						if (!sameScope) {
+							bool isClosure;
+							if (UNEXPECTED(!isInstance(Z_OBJ_P(expr), PT_CLASS_CLOSURE_EXPR, isClosure))) return zv::Val();
+							if (!isClosure && UNEXPECTED(!isInstance(Z_OBJ_P(expr), PT_CLASS_ARROW_FUNCTION, isClosure))) return zv::Val();
+							if (!isClosure) return processExprNodeInternal(stmt, expr, scope, storage, nodeCallback, context);
+						}
+					}
+
 					zv::Val reanchored = pt_expression_result_at_ask_position(storedResult.raw(), scope);
 					if (UNEXPECTED(reanchored.isUndef())) return zv::Val();
 					if (consume && UNEXPECTED(!thisStoreExpressionResult(storage, expr, reanchored.raw()))) return zv::Val();