diff --git a/src/Psalm/Internal/Analyzer/Statements/UnsetAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/UnsetAnalyzer.php
index b66709415..3943db8e4 100644
--- a/src/Psalm/Internal/Analyzer/Statements/UnsetAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/UnsetAnalyzer.php
@@ -51,6 +51,7 @@ class UnsetAnalyzer
                             ) {
                                 if (isset($atomic_root_type->properties[$var->dim->value])) {
                                     unset($atomic_root_type->properties[$var->dim->value]);
+                                    $root_type->bustCache(); //remove id cache
                                 }
 
                                 if (!$atomic_root_type->properties) {