diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
index 970aabe9025..b7eb6c74351 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
@@ -306,7 +306,7 @@ function ($var_id) use ($original_vars_in_scope) {
 
             $context->assigned_var_ids = array_merge(
                 $context->assigned_var_ids,
-                $pre_op_context->assigned_var_ids
+                $op_context->assigned_var_ids
             );
 
             if ($context->collect_references) {