diff --git a/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php b/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
index dfb72aa8f..0afd9db72 100644
--- a/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
@@ -651,7 +651,7 @@ class BinaryOpChecker
                 return;
             }
 
-            if ($right_type->isNullable() && $right_type->ignore_falsable_issues) {
+            if ($right_type->isNullable() && !$right_type->ignore_nullable_issues) {
                 if ($statements_source && IssueBuffer::accepts(
                     new PossiblyNullOperand(
                         'Right operand cannot be nullable, got ' . $right_type,
diff --git a/tests/BinaryOperationTest.php b/tests/BinaryOperationTest.php
index b378560fa..22c542f75 100644
--- a/tests/BinaryOperationTest.php
+++ b/tests/BinaryOperationTest.php
@@ -217,6 +217,11 @@ class BinaryOperationTest extends TestCase
                     $a++;',
                 'error_message' => 'InvalidOperand',
             ],
+            'possiblyDivByZero' => [
+                '<?php
+                    $a = 5 / (rand(0, 1) ? 2 : null);',
+                'error_message' => 'PossiblyNullOperand',
+            ],
         ];
     }
 }