diff --git a/src/Plugins/Shard.php b/src/Plugins/Shard.php
index abd835ea..0a660780 100644
--- a/src/Plugins/Shard.php
+++ b/src/Plugins/Shard.php
@@ -34,7 +34,8 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
      *     index: int,
      *     total: int,
      *     testsRan: int,
-     *     testsCount: int
+     *     testsCount: int,
+     *     estimatedTime: float|null
      * }|null
      */
     private static ?array $shard = null;
@@ -122,11 +123,16 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
             $testsToRun = (array_chunk($tests, max(1, (int) ceil(count($tests) / $total))))[$index - 1] ?? [];
         }
 
+        $estimatedTime = self::$timeBalanced && $timings !== null
+            ? array_sum(array_map(fn (string $test): float => $timings[$test] ?? 0.0, $testsToRun))
+            : null;
+
         self::$shard = [
             'index' => $index,
             'total' => $total,
             'testsRan' => count($testsToRun),
             'testsCount' => count($tests),
+            'estimatedTime' => $estimatedTime,
         ];
 
         return [...$arguments, '--filter', $this->buildFilterArgument($testsToRun)];
@@ -174,7 +180,7 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
             'php',
             ...$this->removeParallelArguments($arguments),
             '--list-tests',
-        ]))->mustRun()->getOutput();
+        ]))->setTimeout(120)->mustRun()->getOutput();
 
         preg_match_all('/ - (?:P\\\\)?(Tests\\\\[^:]+)::/', $output, $matches);
 
@@ -226,8 +232,14 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
             'total' => $total,
             'testsRan' => $testsRan,
             'testsCount' => $testsCount,
+            'estimatedTime' => $estimatedTime,
         ] = self::$shard;
 
+        $suffix = '';
+        if (self::$timeBalanced && is_float($estimatedTime)) {
+            $suffix = sprintf(' <fg=gray>(time-balanced, ~%.1fs)</>', $estimatedTime);
+        }
+
         $this->output->writeln(sprintf(
             '  <fg=gray>Shard:</>    <fg=default>%d of %d</> — %d file%s ran, out of %d%s.',
             $index,
@@ -235,7 +247,7 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
             $testsRan,
             $testsRan === 1 ? '' : 's',
             $testsCount,
-            self::$timeBalanced ? ' <fg=gray>(time-balanced)</>' : '',
+            $suffix,
         ));
 
         return $exitCode;
@@ -364,13 +376,13 @@ final class Shard implements AddsOutput, HandlesArguments, Terminable
         $contents = file_get_contents($path);
 
         if ($contents === false) {
-            return null;
+            throw new InvalidOption('The [tests/.pest/shards.json] file could not be read. Delete it or run [--update-shards] to regenerate.');
         }
 
         $data = json_decode($contents, true);
 
         if (! is_array($data) || ! isset($data['timings']) || ! is_array($data['timings'])) {
-            return null;
+            throw new InvalidOption('The [tests/.pest/shards.json] file is corrupted. Delete it or run [--update-shards] to regenerate.');
         }
 
         /** @var array<string, float> */