diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index 5090d04402..cbed5105ae 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -4141,6 +4141,7 @@ private function enterForeach(MutatingScope $scope, ExpressionResultStorage $sto
 		if (
 			$stmt->expr instanceof FuncCall
 			&& $stmt->expr->name instanceof Name
+			&& !$stmt->expr->isFirstClassCallable()
 			&& $stmt->expr->name->toLowerString() === 'array_keys'
 			&& $stmt->valueVar instanceof Variable
 		) {
@@ -4816,6 +4817,7 @@ private function inferForLoopExpressions(For_ $stmt, Expr $lastCondExpr, Mutatin
 				&& $lastCondExpr->left instanceof Variable
 				&& $lastCondExpr->right instanceof FuncCall
 				&& $lastCondExpr->right->name instanceof Name
+				&& !$lastCondExpr->right->isFirstClassCallable()
 				&& in_array($lastCondExpr->right->name->toLowerString(), ['count', 'sizeof'], true)
 				&& count($lastCondExpr->right->getArgs()) > 0
 				&& $lastCondExpr->right->getArgs()[0]->value instanceof Variable
@@ -4840,6 +4842,7 @@ private function inferForLoopExpressions(For_ $stmt, Expr $lastCondExpr, Mutatin
 				&& $lastCondExpr->right instanceof Variable
 				&& $lastCondExpr->left instanceof FuncCall
 				&& $lastCondExpr->left->name instanceof Name
+				&& !$lastCondExpr->left->isFirstClassCallable()
 				&& in_array($lastCondExpr->left->name->toLowerString(), ['count', 'sizeof'], true)
 				&& count($lastCondExpr->left->getArgs()) > 0
 				&& $lastCondExpr->left->getArgs()[0]->value instanceof Variable
diff --git a/src/Analyser/TypeSpecifier.php b/src/Analyser/TypeSpecifier.php
index 24903779b3..1eacf25dd4 100644
--- a/src/Analyser/TypeSpecifier.php
+++ b/src/Analyser/TypeSpecifier.php
@@ -247,6 +247,7 @@ public function specifyTypesInCondition(
 			if (
 				$expr->left instanceof FuncCall
 				&& $expr->left->name instanceof Name
+				&& !$expr->left->isFirstClassCallable()
 				&& in_array(strtolower((string) $expr->left->name), ['count', 'sizeof', 'strlen', 'mb_strlen', 'preg_match'], true)
 				&& count($expr->left->getArgs()) >= 1
 				&& (
@@ -275,6 +276,7 @@ public function specifyTypesInCondition(
 				!$context->null()
 				&& $expr->right instanceof FuncCall
 				&& $expr->right->name instanceof Name
+				&& !$expr->right->isFirstClassCallable()
 				&& in_array(strtolower((string) $expr->right->name), ['count', 'sizeof'], true)
 				&& count($expr->right->getArgs()) >= 1
 				&& $leftType->isInteger()->yes()
@@ -378,6 +380,7 @@ public function specifyTypesInCondition(
 				&& $expr->right instanceof Expr\BinaryOp\Minus
 				&& $expr->right->left instanceof FuncCall
 				&& $expr->right->left->name instanceof Name
+				&& !$expr->right->left->isFirstClassCallable()
 				&& in_array(strtolower((string) $expr->right->left->name), ['count', 'sizeof'], true)
 				&& count($expr->right->left->getArgs()) >= 1
 				// constant offsets are handled via HasOffsetType/HasOffsetValueType
@@ -404,6 +407,7 @@ public function specifyTypesInCondition(
 				!$context->null()
 				&& $expr->right instanceof FuncCall
 				&& $expr->right->name instanceof Name
+				&& !$expr->right->isFirstClassCallable()
 				&& in_array(strtolower((string) $expr->right->name), ['preg_match'], true)
 				&& count($expr->right->getArgs()) >= 3
 				&& (
@@ -421,6 +425,7 @@ public function specifyTypesInCondition(
 				!$context->null()
 				&& $expr->right instanceof FuncCall
 				&& $expr->right->name instanceof Name
+				&& !$expr->right->isFirstClassCallable()
 				&& in_array(strtolower((string) $expr->right->name), ['strlen', 'mb_strlen'], true)
 				&& count($expr->right->getArgs()) === 1
 				&& $leftType->isInteger()->yes()
@@ -825,6 +830,7 @@ public function specifyTypesInCondition(
 			if (
 				$expr->expr instanceof FuncCall
 				&& $expr->expr->name instanceof Name
+				&& !$expr->expr->isFirstClassCallable()
 				&& in_array($expr->expr->name->toLowerString(), ['array_key_first', 'array_key_last'], true)
 				&& count($expr->expr->getArgs()) >= 1
 			) {
@@ -881,6 +887,7 @@ public function specifyTypesInCondition(
 				if (
 					$expr->expr instanceof FuncCall
 					&& $expr->expr->name instanceof Name
+					&& !$expr->expr->isFirstClassCallable()
 					&& in_array($expr->expr->name->toLowerString(), ['array_rand'], true)
 					&& count($expr->expr->getArgs()) >= 1
 				) {
@@ -911,6 +918,7 @@ public function specifyTypesInCondition(
 					$expr->expr instanceof Expr\BinaryOp\Minus
 					&& $expr->expr->left instanceof FuncCall
 					&& $expr->expr->left->name instanceof Name
+					&& !$expr->expr->left->isFirstClassCallable()
 					&& $expr->expr->right instanceof Node\Scalar\Int_
 					&& $expr->expr->right->value === 1
 					&& in_array($expr->expr->left->name->toLowerString(), ['count', 'sizeof'], true)
@@ -938,6 +946,7 @@ public function specifyTypesInCondition(
 				if (
 					$expr->expr instanceof FuncCall
 					&& $expr->expr->name instanceof Name
+					&& !$expr->expr->isFirstClassCallable()
 					&& $expr->expr->name->toLowerString() === 'array_search'
 					&& count($expr->expr->getArgs()) >= 2
 				) {
@@ -1596,6 +1605,7 @@ private function specifyTypesForConstantStringBinaryExpression(
 		if (
 			$exprNode instanceof FuncCall
 			&& $exprNode->name instanceof Name
+			&& !$exprNode->isFirstClassCallable()
 			&& strtolower($exprNode->name->toString()) === 'gettype'
 			&& isset($exprNode->getArgs()[0])
 		) {
@@ -1636,6 +1646,7 @@ private function specifyTypesForConstantStringBinaryExpression(
 			$context->true()
 			&& $exprNode instanceof FuncCall
 			&& $exprNode->name instanceof Name
+			&& !$exprNode->isFirstClassCallable()
 			&& strtolower((string) $exprNode->name) === 'get_parent_class'
 			&& isset($exprNode->getArgs()[0])
 		) {
@@ -1673,6 +1684,7 @@ private function specifyTypesForConstantStringBinaryExpression(
 			$context->false()
 			&& $exprNode instanceof FuncCall
 			&& $exprNode->name instanceof Name
+			&& !$exprNode->isFirstClassCallable()
 			&& in_array(strtolower((string) $exprNode->name), [
 				'trim', 'ltrim', 'rtrim', 'chop',
 				'mb_trim', 'mb_ltrim', 'mb_rtrim',
@@ -2750,6 +2762,7 @@ public function resolveEqual(Expr\BinaryOp\Equal $expr, Scope $scope, TypeSpecif
 			if (
 				$exprNode instanceof FuncCall
 				&& $exprNode->name instanceof Name
+				&& !$exprNode->isFirstClassCallable()
 				&& in_array(strtolower($exprNode->name->toString()), ['gettype', 'get_class', 'get_debug_type'], true)
 				&& isset($exprNode->getArgs()[0])
 				&& $constantType->isString()->yes()
@@ -2897,6 +2910,7 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 		if (
 			!$context->null()
 			&& $unwrappedLeftExpr instanceof FuncCall
+			&& !$unwrappedLeftExpr->isFirstClassCallable()
 			&& count($unwrappedLeftExpr->getArgs()) >= 1
 			&& $unwrappedLeftExpr->name instanceof Name
 			&& in_array(strtolower((string) $unwrappedLeftExpr->name), ['count', 'sizeof'], true)
@@ -2907,6 +2921,7 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 				$context->true()
 				&& $unwrappedRightExpr instanceof FuncCall
 				&& $unwrappedRightExpr->name instanceof Name
+				&& !$unwrappedRightExpr->isFirstClassCallable()
 				&& in_array($unwrappedRightExpr->name->toLowerString(), ['count', 'sizeof'], true)
 				&& count($unwrappedRightExpr->getArgs()) >= 1
 			) {
@@ -2981,9 +2996,10 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 		if (
 			!$context->null()
 			&& $unwrappedLeftExpr instanceof FuncCall
-			&& count($unwrappedLeftExpr->getArgs()) === 1
 			&& $unwrappedLeftExpr->name instanceof Name
+			&& !$unwrappedLeftExpr->isFirstClassCallable()
 			&& in_array(strtolower((string) $unwrappedLeftExpr->name), ['strlen', 'mb_strlen'], true)
+			&& count($unwrappedLeftExpr->getArgs()) === 1
 			&& $rightType->isInteger()->yes()
 		) {
 			if (IntegerRangeType::fromInterval(null, -1)->isSuperTypeOf($rightType)->yes()) {
@@ -3019,6 +3035,7 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 		if (
 			$unwrappedLeftExpr instanceof FuncCall
 			&& $unwrappedLeftExpr->name instanceof Name
+			&& !$unwrappedLeftExpr->isFirstClassCallable()
 			&& in_array($unwrappedLeftExpr->name->toLowerString(), ['array_key_first', 'array_key_last'], true)
 			&& isset($unwrappedLeftExpr->getArgs()[0])
 			&& $rightType->isNull()->yes()
@@ -3050,6 +3067,7 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 			$context->true()
 			&& $unwrappedLeftExpr instanceof FuncCall
 			&& $unwrappedLeftExpr->name instanceof Name
+			&& !$unwrappedLeftExpr->isFirstClassCallable()
 			&& in_array(strtolower($unwrappedLeftExpr->name->toString()), ['get_class', 'get_debug_type'], true)
 			&& isset($unwrappedLeftExpr->getArgs()[0])
 		) {
@@ -3075,6 +3093,7 @@ private function resolveNormalizedIdentical(Expr\BinaryOp\Identical $expr, Scope
 			$context->truthy()
 			&& $unwrappedLeftExpr instanceof FuncCall
 			&& $unwrappedLeftExpr->name instanceof Name
+			&& !$unwrappedLeftExpr->isFirstClassCallable()
 			&& in_array(strtolower($unwrappedLeftExpr->name->toString()), [
 				'substr', 'strstr', 'stristr', 'strchr', 'strrchr', 'strtolower', 'strtoupper', 'ucfirst', 'lcfirst',
 				'mb_substr', 'mb_strstr', 'mb_stristr', 'mb_strchr', 'mb_strrchr', 'mb_strtolower', 'mb_strtoupper', 'mb_ucfirst', 'mb_lcfirst',
diff --git a/tests/PHPStan/Analyser/AnalyserIntegrationTest.php b/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
index 135aad26f8..7522b5475f 100644
--- a/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
+++ b/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
@@ -1550,6 +1550,13 @@ public function testBug14542(): void
 		$this->assertNoErrors($errors);
 	}
 
+	public function testBug14550(): void
+	{
+		// crash
+		$errors = $this->runAnalyse(__DIR__ . '/data/bug-14550.php');
+		$this->assertNotEmpty($errors);
+	}
+
 	/**
 	 * @param string[]|null $allAnalysedFiles
 	 * @return list<Error>
diff --git a/tests/PHPStan/Analyser/data/bug-14550.php b/tests/PHPStan/Analyser/data/bug-14550.php
new file mode 100644
index 0000000000..95b5ecb4ac
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/bug-14550.php
@@ -0,0 +1,130 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug14550;
+
+function testArrayKeyFirstAssign(): void
+{
+	$fn = array_key_first(...);
+}
+
+function testArrayKeyLastAssign(): void
+{
+	$fn = array_key_last(...);
+}
+
+function testArrayRandAssign(): void
+{
+	$fn = array_rand(...);
+}
+
+function testCountMinusOneAssign(): void
+{
+	$idx = count(...) - 1;
+}
+
+function testArraySearchInCondition(): void
+{
+	if ($key = array_search(...)) {
+	}
+}
+
+function testCountInComparisons(): void
+{
+	if (count(...) < 1) {}
+	if (0 < count(...)) {}
+}
+
+function testSizeofInComparisons(): void
+{
+	if (sizeof(...) < 1) {}
+	if (0 < sizeof(...)) {}
+}
+
+function testCountMinusOneInComparison(): void
+{
+	$i = 0;
+	if ($i < count(...) - 1) {}
+}
+
+function testStrlenInComparisons(): void
+{
+	if (strlen(...) < 1) {}
+	if (0 < strlen(...)) {}
+}
+
+function testMbStrlenInComparisons(): void
+{
+	if (mb_strlen(...) < 1) {}
+	if (0 < mb_strlen(...)) {}
+}
+
+function testPregMatchInComparisons(): void
+{
+	if (preg_match(...) < 1) {}
+	if (0 < preg_match(...)) {}
+}
+
+function testCountIdentical(): void
+{
+	if (count(...) === 0) {}
+}
+
+function testStrlenIdentical(): void
+{
+	if (strlen(...) === 0) {}
+	if (mb_strlen(...) === 0) {}
+}
+
+function testArrayKeyFirstNullComparison(): void
+{
+	if (array_key_first(...) !== null) {}
+	if (array_key_last(...) !== null) {}
+}
+
+function testGetClassIdentical(): void
+{
+	if (get_class(...) === 'stdClass') {}
+	if (get_debug_type(...) === 'string') {}
+}
+
+function testStringFuncIdentical(): void
+{
+	if (strtolower(...) === 'test') {}
+}
+
+function testGettypeEquality(): void
+{
+	if (gettype(...) === 'string') {}
+	if (gettype(...) == 'string') {}
+}
+
+function testGetClassEquality(): void
+{
+	if (get_class(...) == 'stdClass') {}
+	if (get_debug_type(...) == 'string') {}
+}
+
+function testGetParentClassEquality(): void
+{
+	if (get_parent_class(...) === 'stdClass') {}
+}
+
+function testTrimEquality(): void
+{
+	if (trim(...) !== '') {}
+	if (ltrim(...) !== '') {}
+	if (rtrim(...) !== '') {}
+}
+
+function testArrayKeysInForeach(): void
+{
+	foreach (array_keys(...) as $key) {}
+}
+
+function testCountInForLoop(): void
+{
+	for ($i = 0; $i < count(...); $i++) {}
+	for ($i = 0; count(...) > $i; $i++) {}
+}