diff --git a/src/Illuminate/Collections/Traits/EnumeratesValues.php b/src/Illuminate/Collections/Traits/EnumeratesValues.php
index 9fa86d5bac05..aee186f0c209 100644
--- a/src/Illuminate/Collections/Traits/EnumeratesValues.php
+++ b/src/Illuminate/Collections/Traits/EnumeratesValues.php
@@ -535,8 +535,10 @@ public function percentage(callable $callback, int $precision = 2)
     /**
      * Get the sum of the given values.
      *
-     * @param  (callable(TValue): mixed)|string|null  $callback
-     * @return mixed
+     * @template TReturnType
+     *
+     * @param  (callable(TValue): TReturnType)|string|null  $callback
+     * @return ($callback is callable ? TReturnType : mixed)
      */
     public function sum($callback = null)
     {
diff --git a/types/Support/Collection.php b/types/Support/Collection.php
index 05a5b79fcd46..c6733fa5d331 100644
--- a/types/Support/Collection.php
+++ b/types/Support/Collection.php
@@ -873,10 +873,10 @@ function ($collection, $count) {
 assertType('Illuminate\Support\Collection<string, string>', $collection->make(['string' => 'string'])->sortKeysDesc(1));
 
 assertType('mixed', $collection->make([1])->sum('string'));
-assertType('mixed', $collection->make(['string'])->sum(function ($string) {
+assertType('int<1, 2>', $collection->make(['string'])->sum(function ($string) {
     assertType('string', $string);
 
-    return 1;
+    return rand(1, 2);
 }));
 
 assertType('Illuminate\Support\Collection<int, int>', $collection->make([1])->take(1));
diff --git a/types/Support/LazyCollection.php b/types/Support/LazyCollection.php
index 7c1359f58a40..4e96ba431f70 100644
--- a/types/Support/LazyCollection.php
+++ b/types/Support/LazyCollection.php
@@ -732,10 +732,10 @@ public function toArray(): array
 assertType('Illuminate\Support\LazyCollection<string, string>', $collection->make(['string' => 'string'])->sortKeysDesc(1));
 
 assertType('mixed', $collection->make([1])->sum('string'));
-assertType('mixed', $collection->make(['string'])->sum(function ($string) {
+assertType('int<1, 2>', $collection->make(['string'])->sum(function ($string) {
     assertType('string', $string);
 
-    return 1;
+    return rand(1, 2);
 }));
 
 assertType('Illuminate\Support\LazyCollection<int, int>', $collection->make([1])->take(1));