diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 4d6754c7c..13d8ff69f 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -46,7 +46,7 @@ parameters:
 			path: src/Collection.php
 
 		-
-			message: "#^Parameter \\#1 \\$ of closure expects callable\\(mixed, mixed, mixed, iterable\\)\\: mixed, callable\\(T\\|V, T, TKey, Iterator\\<TKey, T\\>\\)\\: V given\\.$#"
+			message: "#^Parameter \\#1 \\$ of closure expects callable\\(mixed, mixed, mixed, iterable\\)\\: mixed, callable\\(T\\|V, T, TKey, Iterator\\<TKey, T\\>\\)\\: T\\|V given\\.$#"
 			count: 4
 			path: src/Collection.php
 
diff --git a/src/Contract/Operation/FoldLeft1able.php b/src/Contract/Operation/FoldLeft1able.php
index d77e03f88..e2c41edfd 100644
--- a/src/Contract/Operation/FoldLeft1able.php
+++ b/src/Contract/Operation/FoldLeft1able.php
@@ -21,7 +21,7 @@ interface FoldLeft1able
      *
      * @template V
      *
-     * @param callable(T|V, T, TKey, Iterator<TKey, T>): V $callback
+     * @param callable(T|V, T, TKey, Iterator<TKey, T>): (T|V) $callback
      *
      * @return T|V|null
      */
diff --git a/src/Contract/Operation/FoldRight1able.php b/src/Contract/Operation/FoldRight1able.php
index 94de61eab..d149a9dc6 100644
--- a/src/Contract/Operation/FoldRight1able.php
+++ b/src/Contract/Operation/FoldRight1able.php
@@ -15,7 +15,7 @@ interface FoldRight1able
     /**
      * @template V
      *
-     * @param callable(T|V, T, TKey, Iterator<TKey, T>): V $callback
+     * @param callable(T|V, T, TKey, Iterator<TKey, T>): (T|V) $callback
      *
      * @return T|V|null
      */
diff --git a/src/Contract/Operation/ScanLeft1able.php b/src/Contract/Operation/ScanLeft1able.php
index 30cd20cf7..27e70fd46 100644
--- a/src/Contract/Operation/ScanLeft1able.php
+++ b/src/Contract/Operation/ScanLeft1able.php
@@ -22,7 +22,7 @@ interface ScanLeft1able
      *
      * @template V
      *
-     * @param callable(T|V, T, TKey, Iterator<TKey, T>): V $callback
+     * @param callable(T|V, T, TKey, Iterator<TKey, T>): (T|V) $callback
      *
      * @return Collection<int|TKey, T|V>
      */
diff --git a/src/Contract/Operation/ScanRight1able.php b/src/Contract/Operation/ScanRight1able.php
index 46a85529b..21b73b337 100644
--- a/src/Contract/Operation/ScanRight1able.php
+++ b/src/Contract/Operation/ScanRight1able.php
@@ -22,7 +22,7 @@ interface ScanRight1able
      *
      * @template V
      *
-     * @param callable(T|V, T, TKey, Iterator<TKey, T>): V $callback
+     * @param callable(T|V, T, TKey, Iterator<TKey, T>): (T|V) $callback
      *
      * @return Collection<int|TKey, T|V>
      */