diff --git a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
index fa3e3de6f7f..382cd907233 100644
--- a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
@@ -2238,10 +2238,9 @@ private static function reconcileFalsyOrEmpty(
             //if any atomic in the union is either always truthy, we remove it. If not always falsy, we mark the check
             //as not redundant.
             $union = new Union([$existing_var_type_part]);
-            if (!$existing_var_type->possibly_undefined
-                && !$existing_var_type->possibly_undefined_from_try
-                && $union->isAlwaysTruthy()
-            ) {
+            $union->possibly_undefined = $existing_var_type->possibly_undefined;
+            $union->possibly_undefined_from_try = $existing_var_type->possibly_undefined_from_try;
+            if ($union->isAlwaysTruthy()) {
                 $did_remove_type = true;
                 $existing_var_type->removeType($existing_var_type_key);
             } elseif (!$union->isAlwaysFalsy()) {
diff --git a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
index 4a5d05a7bd1..0aec7c76fbc 100644
--- a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
@@ -591,13 +591,12 @@ private static function reconcileFalsyOrEmpty(
             //if any atomic in the union is either always falsy, we remove it. If not always truthy, we mark the check
             //as not redundant.
             $union = new Union([$existing_var_type_part]);
+            $union->possibly_undefined = $existing_var_type->possibly_undefined;
+            $union->possibly_undefined_from_try = $existing_var_type->possibly_undefined_from_try;
             if ($union->isAlwaysFalsy()) {
                 $did_remove_type = true;
                 $existing_var_type->removeType($existing_var_type_key);
-            } elseif ($existing_var_type->possibly_undefined
-                || $existing_var_type->possibly_undefined_from_try
-                || !$union->isAlwaysTruthy()
-            ) {
+            } elseif (!$union->isAlwaysTruthy()) {
                 $did_remove_type = true;
             }
         }
diff --git a/src/Psalm/Type/Union.php b/src/Psalm/Type/Union.php
index cfb719a7cf7..1ec86d4b06f 100644
--- a/src/Psalm/Type/Union.php
+++ b/src/Psalm/Type/Union.php
@@ -1083,6 +1083,10 @@ public function isTrue(): bool
 
     public function isAlwaysTruthy(): bool
     {
+        if ($this->possibly_undefined || $this->possibly_undefined_from_try) {
+            return false;
+        }
+
         foreach ($this->getAtomicTypes() as $atomic_type) {
             if ($atomic_type instanceof TTrue) {
                 continue;