diff --git a/src/Psalm/Type/Atomic/TCallableString.php b/src/Psalm/Type/Atomic/TCallableString.php
index 25b1edb0d4e..cf6f1d78a51 100644
--- a/src/Psalm/Type/Atomic/TCallableString.php
+++ b/src/Psalm/Type/Atomic/TCallableString.php
@@ -4,7 +4,7 @@
 /**
  * Denotes the `callable-string` type, used to represent an unknown string that is also `callable`.
  */
-class TCallableString extends TNonEmptyString
+class TCallableString extends TNonFalsyString
 {
 
     public function getKey(bool $include_extra = true): string