maybe-fix.diff

diff --git a/src/Psalm/Issue/PropertyIssue.php b/src/Psalm/Issue/PropertyIssue.php
index f64cd6cc4..4d0befda1 100644
--- a/src/Psalm/Issue/PropertyIssue.php
+++ b/src/Psalm/Issue/PropertyIssue.php
@@ -4,6 +4,8 @@ namespace Psalm\Issue;
 
 use Psalm\CodeLocation;
 
+use function get_class;
+
 abstract class PropertyIssue extends CodeIssue
 {
     /**
@@ -18,5 +20,6 @@ abstract class PropertyIssue extends CodeIssue
     ) {
         parent::__construct($message, $code_location);
         $this->property_id = $property_id;
+        $this->dupe_key = get_class($this) . $property_id;
     }
 }