diff --git a/src/Psalm/Internal/Type/AssertionReconciler.php b/src/Psalm/Internal/Type/AssertionReconciler.php
index 4387bd020..161147fdb 100644
--- a/src/Psalm/Internal/Type/AssertionReconciler.php
+++ b/src/Psalm/Internal/Type/AssertionReconciler.php
@@ -1658,7 +1658,13 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                             $const_type_atomic = $const_type_atomic->getGenericArrayType();
                         }
 
-                        return clone $const_type_atomic->type_params[0];
+                        if (TypeAnalyzer::isContainedBy(
+                            $codebase,
+                            $const_type_atomic->type_params[0],
+                            $existing_var_type
+                        )) {
+                            return clone $const_type_atomic->type_params[0];
+                        }
                     }
                 }
             }
diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
index 5838048e2..b78abcbb6 100644
--- a/tests/ArrayFunctionCallTest.php
+++ b/tests/ArrayFunctionCallTest.php
@@ -1324,6 +1324,24 @@ class ArrayFunctionCallTest extends TestCase
                         return $elements;
                     }'
             ],
+            'arrayKeyExistsShoudldNotModifyIntType' => [
+                '<?php
+                    class HttpError {
+                        const ERRS = [
+                            403 => "a",
+                            404 => "b",
+                            500 => "c"
+                        ];
+                    }
+
+                    function init(string $code) : string {
+                        if (array_key_exists($code, HttpError::ERRS)) {
+                            return $code;
+                        }
+
+                        return "";
+                    }'
+            ],
         ];
     }