diff --git a/dictionaries/ImpureFunctionsList.php b/dictionaries/ImpureFunctionsList.php
index 70b1fad7d..d3a3f7ce0 100644
--- a/dictionaries/ImpureFunctionsList.php
+++ b/dictionaries/ImpureFunctionsList.php
@@ -67,6 +67,8 @@ return [
     'socket_set_block' => true,
     'socket_set_nonblock' => true,
     'socket_listen' => true,
+    'stream_socket_shutdown' => true,
+    'socket_shutdown' => true,
     // meta calls
     'call_user_func' => true,
     'call_user_func_array' => true,
@@ -93,7 +95,6 @@ return [
     'mcrypt_generic_deinit' => true,
     'mcrypt_module_close' => true,
     // internal optimisation
-    'opcache_compile_file' => true,
     'clearstatcache' => true,
     // process-related
     'pcntl_signal' => true,
diff --git a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
index 3c0b6f2bd..4e93704e2 100644
--- a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
@@ -1260,6 +1260,17 @@ abstract class FunctionLikeAnalyzer extends SourceAnalyzer
                     );
                 }
 
+                if ($param_type->isNever()) {
+                    IssueBuffer::maybeAdd(
+                        new ReservedWord(
+                            'Parameter cannot be never',
+                            $function_param->type_location,
+                            'never',
+                        ),
+                        $this->suppressed_issues,
+                    );
+                }
+
                 if ($param_type->check(
                     $this->source,
                     $function_param->type_location,
diff --git a/src/Psalm/Internal/Analyzer/MethodComparator.php b/src/Psalm/Internal/Analyzer/MethodComparator.php
index 82e1c6c48..d595df158 100644
--- a/src/Psalm/Internal/Analyzer/MethodComparator.php
+++ b/src/Psalm/Internal/Analyzer/MethodComparator.php
@@ -313,6 +313,16 @@ class MethodComparator
             );
         }
 
+        if ($guide_method_storage->returns_by_ref && !$implementer_method_storage->returns_by_ref) {
+            IssueBuffer::maybeAdd(
+                new MethodSignatureMismatch(
+                    'Method ' . $cased_implementer_method_id . ' must return by-reference',
+                    $code_location,
+                ),
+                $suppressed_issues + $implementer_classlike_storage->suppressed_issues,
+            );
+        }
+
         if ($guide_method_storage->external_mutation_free
             && !$implementer_method_storage->external_mutation_free
             && !$guide_method_storage->mutation_free_inferred
diff --git a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
index dfe109cc0..55e80d446 100644
--- a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
@@ -678,7 +678,11 @@ class StatementsAnalyzer extends SourceAnalyzer
                 } else {
                     try {
                         $checked_type = $context->vars_in_scope[$checked_var_id];
-                        $check_type = Type::parseString($check_type_string);
+                        $fq_check_type_string = Type::getFQCLNFromString(
+                            $check_type_string,
+                            $statements_analyzer->getAliases(),
+                        );
+                        $check_type = Type::parseString($fq_check_type_string);
                         /** @psalm-suppress InaccessibleProperty We just created this type */
                         $check_type->possibly_undefined = $possibly_undefined;
 
diff --git a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
index f4de672c9..ab7da8730 100644
--- a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
@@ -122,6 +122,11 @@ class NegatedAssertionReconciler extends Reconciler
             $existing_var_type->removeType('array');
         }
 
+        if ($assertion instanceof IsNotType && $assertion_type instanceof TClassString) {
+            $existing_var_type->removeType(TClassString::class);
+            $existing_var_type->addType(new TString);
+        }
+
         if (!$is_equality
             && isset($existing_var_atomic_types['int'])
             && $existing_var_type->from_calculation
diff --git a/src/Psalm/Internal/Type/ParseTreeCreator.php b/src/Psalm/Internal/Type/ParseTreeCreator.php
index 9fdd3fcc4..0ea260804 100644
--- a/src/Psalm/Internal/Type/ParseTreeCreator.php
+++ b/src/Psalm/Internal/Type/ParseTreeCreator.php
@@ -235,6 +235,46 @@ class ParseTreeCreator
         $this->current_leaf = $new_parent_leaf;
     }
 
+    /**
+     * @param  array{0: string, 1: int, 2?: string} $current_token
+     */
+    private function parseCallableParam(array $current_token, ParseTree $current_parent): void
+    {
+        $variadic = false;
+        $has_default = false;
+
+        if ($current_token[0] === '&') {
+            ++$this->t;
+            $current_token = $this->t < $this->type_token_count ? $this->type_tokens[$this->t] : null;
+        } elseif ($current_token[0] === '...') {
+            $variadic = true;
+
+            ++$this->t;
+            $current_token = $this->t < $this->type_token_count ? $this->type_tokens[$this->t] : null;
+        } elseif ($current_token[0] === '=') {
+            $has_default = true;
+
+            ++$this->t;
+            $current_token = $this->t < $this->type_token_count ? $this->type_tokens[$this->t] : null;
+        }
+
+        if (!$current_token || $current_token[0][0] !== '$') {
+            throw new TypeParseTreeException('Unexpected token after space');
+        }
+
+        $new_leaf = new CallableParamTree($current_parent);
+        $new_leaf->has_default = $has_default;
+        $new_leaf->variadic = $variadic;
+
+        if ($current_parent !== $this->current_leaf) {
+            $new_leaf->children = [$this->current_leaf];
+            array_pop($current_parent->children);
+        }
+        $current_parent->children[] = $new_leaf;
+
+        $this->current_leaf = $new_leaf;
+    }
+
     private function handleLessThan(): void
     {
         if (!$this->current_leaf instanceof FieldEllipsis) {
@@ -553,24 +593,27 @@ class ParseTreeCreator
 
         $current_parent = $this->current_leaf->parent;
 
-        if ($current_parent instanceof CallableTree) {
-            return;
-        }
-
-        while ($current_parent && !$current_parent instanceof MethodTree) {
+        //while ($current_parent && !$method_or_callable_parent) {
+        while ($current_parent && !$current_parent instanceof MethodTree && !$current_parent instanceof CallableTree) {
             $this->current_leaf = $current_parent;
             $current_parent = $current_parent->parent;
         }
 
         $next_token = $this->t + 1 < $this->type_token_count ? $this->type_tokens[$this->t + 1] : null;
 
-        if (!$current_parent instanceof MethodTree || !$next_token) {
+        if (!($current_parent instanceof MethodTree || $current_parent instanceof CallableTree) || !$next_token) {
             throw new TypeParseTreeException('Unexpected space');
         }
 
-        ++$this->t;
 
-        $this->createMethodParam($next_token, $current_parent);
+        if ($current_parent instanceof MethodTree) {
+            ++$this->t;
+            $this->createMethodParam($next_token, $current_parent);
+        }
+        if ($current_parent instanceof CallableTree) {
+            ++$this->t;
+            $this->parseCallableParam($next_token, $current_parent);
+        }
     }
 
     private function handleQuestionMark(): void
diff --git a/src/Psalm/Issue/InternalClass.php b/src/Psalm/Issue/InternalClass.php
index 827c90134..087eece02 100644
--- a/src/Psalm/Issue/InternalClass.php
+++ b/src/Psalm/Issue/InternalClass.php
@@ -3,6 +3,7 @@
 namespace Psalm\Issue;
 
 use function array_pop;
+use function array_unique;
 use function count;
 use function implode;
 use function reset;
@@ -15,6 +16,7 @@ final class InternalClass extends ClassIssue
     /** @param non-empty-list<non-empty-string> $words */
     public static function listToPhrase(array $words): string
     {
+        $words = array_unique($words);
         if (count($words) === 1) {
             return reset($words);
         }
diff --git a/tests/CheckTypeTest.php b/tests/CheckTypeTest.php
index a3f0aabbf..457c496db 100644
--- a/tests/CheckTypeTest.php
+++ b/tests/CheckTypeTest.php
@@ -18,6 +18,26 @@ class CheckTypeTest extends TestCase
                 $foo = 1;
             ',
         ];
+        yield 'allowNamespace' => [
+            'code' => '<?php
+
+                namespace X;
+
+                final class A {}
+
+                $_a = new A();
+                /** @psalm-check-type-exact $_a = A */',
+        ];
+        yield 'allowImport' => [
+            'code' => '<?php
+
+                namespace X;
+
+                use \stdClass;
+
+                $_a = new stdClass();
+                /** @psalm-check-type-exact $_a = \stdClass */',
+        ];
     }
 
     public function providerInvalidCodeParse(): iterable
diff --git a/tests/ClassLikeStringTest.php b/tests/ClassLikeStringTest.php
index b3bcca561..7970dae84 100644
--- a/tests/ClassLikeStringTest.php
+++ b/tests/ClassLikeStringTest.php
@@ -611,6 +611,18 @@ class ClassLikeStringTest extends TestCase
                         new \RuntimeException();
                     }',
             ],
+            'convertToStringClassExistsNegated' => [
+                'code' => '<?php
+                    /** @param class-string $className */
+                    $className = stdClass::class;
+                    if (class_exists($className)) {
+                        throw new \RuntimeException($className);
+                    }',
+                'assertions' => [
+                    '$className===' => 'string',
+                ],
+
+            ],
             'createNewObjectFromGetClass' => [
                 'code' => '<?php
                     /**
diff --git a/tests/FunctionCallTest.php b/tests/FunctionCallTest.php
index 23f9dcb08..f712af9da 100644
--- a/tests/FunctionCallTest.php
+++ b/tests/FunctionCallTest.php
@@ -3031,6 +3031,17 @@ class FunctionCallTest extends TestCase
                     }',
                 'error_message' => 'InvalidScalarArgument',
             ],
+            'disallowNeverTypeForParam' => [
+                'code' => '<?php
+                    function foo(never $_): void
+                    {
+                        return;
+                    }
+                    ',
+                'error_message' => 'ReservedWord',
+                'ignored_issues' => [],
+                'php_version' => '8.1',
+            ],
         ];
     }
 
diff --git a/tests/MethodSignatureTest.php b/tests/MethodSignatureTest.php
index 4c65719ee..61cd41b9b 100644
--- a/tests/MethodSignatureTest.php
+++ b/tests/MethodSignatureTest.php
@@ -929,6 +929,34 @@ class MethodSignatureTest extends TestCase
                     }
                 ',
             ],
+            'allowByRefReturn' => [
+                'code' => '<?php
+                    interface Foo {
+                        public function &foo(): int;
+                    }
+
+                    class Bar implements Foo {
+                        private int $x = 0;
+                        public function &foo(): int {
+                            return $this->x;
+                        }
+                    }
+                ',
+            ],
+            'descendantAddsByRefReturn' => [
+                'code' => '<?php
+                    interface Foo {
+                        public function foo(): int;
+                    }
+
+                    class Bar implements Foo {
+                        private int $x = 0;
+                        public function &foo(): int {
+                            return $this->x;
+                        }
+                    }
+                ',
+            ],
         ];
     }
 
@@ -1586,6 +1614,20 @@ class MethodSignatureTest extends TestCase
                 'ignored_issues' => [],
                 'php_version' => '8.1',
             ],
+            'absentByRefReturnInDescendant' => [
+                'code' => '<?php
+                    interface Foo {
+                        public function &foo(): int;
+                    }
+
+                    class Bar implements Foo {
+                        public function foo(): int {
+                            return 1;
+                        }
+                    }
+                ',
+                'error_message' => 'MethodSignatureMismatch',
+            ],
         ];
     }
 }
diff --git a/tests/TypeAnnotationTest.php b/tests/TypeAnnotationTest.php
index 8cd1fb218..29ee8f658 100644
--- a/tests/TypeAnnotationTest.php
+++ b/tests/TypeAnnotationTest.php
@@ -679,6 +679,68 @@ class TypeAnnotationTest extends TestCase
                     '$output===' => 'callable():int',
                 ],
             ],
+            'callableFormats' => [
+                'code' => '<?php
+                    /**
+                     * @psalm-type A callable(int, int): string
+                     * @psalm-type B callable(int, int=): string
+                     * @psalm-type C callable(int $a, string $b): void
+                     * @psalm-type D callable(string $c): mixed
+                     * @psalm-type E callable(string $c): mixed
+                     * @psalm-type F callable(float...): (int|null)
+                     * @psalm-type G callable(float ...$d): (int|null)
+                     * @psalm-type H callable(array<int>): array<string>
+                     * @psalm-type I callable(array<string, int> $e): array<int, string>
+                     * @psalm-type J callable(array<int> ...): string
+                     * @psalm-type K callable(array<int> ...$e): string
+                     * @psalm-type L \Closure(int, int): string
+                     *
+                     * @method ma(): A
+                     * @method mb(): B
+                     * @method mc(): C
+                     * @method md(): D
+                     * @method me(): E
+                     * @method mf(): F
+                     * @method mg(): G
+                     * @method mh(): H
+                     * @method mi(): I
+                     * @method mj(): J
+                     * @method mk(): K
+                     * @method ml(): L
+                     */
+                    class Foo {
+                        public function __call(string $method, array $params) { return 1; }
+                    }
+
+                    $foo = new \Foo();
+                    $output_ma = $foo->ma();
+                    $output_mb = $foo->mb();
+                    $output_mc = $foo->mc();
+                    $output_md = $foo->md();
+                    $output_me = $foo->me();
+                    $output_mf = $foo->mf();
+                    $output_mg = $foo->mg();
+                    $output_mh = $foo->mh();
+                    $output_mi = $foo->mi();
+                    $output_mj = $foo->mj();
+                    $output_mk = $foo->mk();
+                    $output_ml = $foo->ml();
+                ',
+                'assertions' => [
+                    '$output_ma===' => 'callable(int, int):string',
+                    '$output_mb===' => 'callable(int, int=):string',
+                    '$output_mc===' => 'callable(int, string):void',
+                    '$output_md===' => 'callable(string):mixed',
+                    '$output_me===' => 'callable(string):mixed',
+                    '$output_mf===' => 'callable(float...):(int|null)',
+                    '$output_mg===' => 'callable(float...):(int|null)',
+                    '$output_mh===' => 'callable(array<array-key, int>):array<array-key, string>',
+                    '$output_mi===' => 'callable(array<string, int>):array<int, string>',
+                    '$output_mj===' => 'callable(array<array-key, int>...):string',
+                    '$output_mk===' => 'callable(array<array-key, int>...):string',
+                    '$output_ml===' => 'Closure(int, int):string',
+                ],
+            ],
             'unionOfStringsContainingBraceChar' => [
                 'code' => '<?php
                     /** @psalm-type T \'{\'|\'}\' */