diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
index e9dbe849702..6e9e525ba52 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -779,8 +779,10 @@ public static function processFunctionCall(
                 $class_string_type = new TClassString();
                 if ($class_exists_check_type === 1) {
                     $class_string_type->is_loaded = true;
+                    $if_types[$first_var_name] = [[new IsIdentical($class_string_type)]];
+                } else {
+                    $if_types[$first_var_name] = [[new IsType($class_string_type)]];
                 }
-                $if_types[$first_var_name] = [[new IsType($class_string_type)]];
             }
         } elseif ($class_exists_check_type = self::hasTraitExistsCheck($expr)) {
             if ($first_var_name) {
diff --git a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
index ab2a8bc2f89..32476d2d378 100644
--- a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
@@ -182,7 +182,7 @@ public static function reconcile(
             $existing_var_type->removeType('array-key');
             $existing_var_type->addType(new TString);
         } elseif ($assertion instanceof IsClassNotEqual) {
-            $assertion_type = Atomic::create($assertion->type);
+            // do nothing
         } elseif ($existing_var_type->isSingle()
             && $existing_var_type->hasNamedObjectType()
             && $assertion_type instanceof TNamedObject
diff --git a/src/Psalm/Internal/Type/TypeCombination.php b/src/Psalm/Internal/Type/TypeCombination.php
index d45af1cef99..c7770a32c26 100644
--- a/src/Psalm/Internal/Type/TypeCombination.php
+++ b/src/Psalm/Internal/Type/TypeCombination.php
@@ -38,6 +38,9 @@ class TypeCombination
     /** @var array<int, bool>|null */
     public $array_counts = [];
 
+    /** @var array<int, bool>|null */
+    public $array_min_counts = [];
+
     /** @var bool */
     public $array_sometimes_filled = false;
 
diff --git a/src/Psalm/Internal/Type/TypeCombiner.php b/src/Psalm/Internal/Type/TypeCombiner.php
index 5aad86c0510..edd502163d6 100644
--- a/src/Psalm/Internal/Type/TypeCombiner.php
+++ b/src/Psalm/Internal/Type/TypeCombiner.php
@@ -545,6 +545,14 @@ private static function scrapeTypeProperties(
                     }
                 }
 
+                if ($combination->array_min_counts !== null) {
+                    if ($type->min_count === null) {
+                        $combination->array_min_counts = null;
+                    } else {
+                        $combination->array_min_counts[$type->min_count] = true;
+                    }
+                }
+
                 $combination->array_sometimes_filled = true;
             } else {
                 $combination->array_always_filled = false;
@@ -586,6 +594,14 @@ private static function scrapeTypeProperties(
                     }
                 }
 
+                if ($combination->array_min_counts !== null) {
+                    if ($type->min_count === null) {
+                        $combination->array_min_counts = null;
+                    } else {
+                        $combination->array_min_counts[$type->min_count] = true;
+                    }
+                }
+
                 $combination->array_sometimes_filled = true;
             } else {
                 $combination->array_always_filled = false;
@@ -717,6 +733,16 @@ private static function scrapeTypeProperties(
                 $combination->array_counts[count($type->properties)] = true;
             }
 
+            if ($combination->array_min_counts !== null) {
+                $min_prop_count = count(
+                    array_filter(
+                        $type->properties,
+                        fn($p) => $p->possibly_undefined
+                    )
+                );
+                $combination->array_min_counts[$min_prop_count] = true;
+            }
+
             foreach ($possibly_undefined_entries as $possibly_undefined_type) {
                 $possibly_undefined_type->possibly_undefined = true;
             }
@@ -1483,6 +1509,11 @@ private static function getArrayTypeFromGenericParams(
                         /** @psalm-suppress PropertyTypeCoercion */
                         $array_type->count = array_keys($combination->array_counts)[0];
                     }
+
+                    if ($combination->array_min_counts) {
+                        /** @psalm-suppress PropertyTypeCoercion */
+                        $array_type->min_count = min(array_keys($combination->array_min_counts));
+                    }
                 }
             } else {
                 $array_type = new TNonEmptyArray($generic_type_params);
@@ -1491,6 +1522,11 @@ private static function getArrayTypeFromGenericParams(
                     /** @psalm-suppress PropertyTypeCoercion */
                     $array_type->count = array_keys($combination->array_counts)[0];
                 }
+
+                if ($combination->array_min_counts) {
+                    /** @psalm-suppress PropertyTypeCoercion */
+                    $array_type->min_count = min(array_keys($combination->array_min_counts));
+                }
             }
         } else {
             if ($combination->all_arrays_class_string_maps
diff --git a/tests/ArrayAccessTest.php b/tests/ArrayAccessTest.php
index 89d681d7e1c..eef2404dd00 100644
--- a/tests/ArrayAccessTest.php
+++ b/tests/ArrayAccessTest.php
@@ -317,6 +317,30 @@ function bar(array $list) : void {
         $this->analyzeFile('somefile.php', new Context());
     }
 
+    public function testCountOnKeyedArrayInRangeWithUpdate(): void
+    {
+        Config::getInstance()->ensure_array_int_offsets_exist = true;
+
+        $this->addFile(
+            'somefile.php',
+            '<?php
+                /** @param non-empty-list<string> $list */
+                function bar(array $list) : void {
+                    if (rand(0, 1)) {
+                        $list = ["a"];
+                    }
+                    if (count($list) > 1) {
+                        if ($list[1][0] === "a") {
+                            $list[1] = "foo";
+                        }
+                        echo $list[1];
+                    }
+                }'
+        );
+
+        $this->analyzeFile('somefile.php', new Context());
+    }
+
     public function testCountOnKeyedArrayOutOfRange(): void
     {
         Config::getInstance()->ensure_array_int_offsets_exist = true;