diff --git a/src/Analyser/ExpressionTypeHolder.php b/src/Analyser/ExpressionTypeHolder.php
index bb598d8fb1..c904db8d7d 100644
--- a/src/Analyser/ExpressionTypeHolder.php
+++ b/src/Analyser/ExpressionTypeHolder.php
@@ -26,6 +26,10 @@ public static function createMaybe(Expr $expr, Type $type): self
 
 	public function equals(self $other): bool
 	{
+		if ($this === $other) {
+			return true;
+		}
+
 		if (!$this->certainty->equals($other->certainty)) {
 			return false;
 		}