diff --git a/src/Plugins/Shard.php b/src/Plugins/Shard.php
index f48260bb5..80e6740d2 100644
--- a/src/Plugins/Shard.php
+++ b/src/Plugins/Shard.php
@@ -85,7 +85,7 @@ private function allTests(array $arguments): array
     {
         $output = (new Process([
             'php',
-            ...$this->removeParallelArguments($arguments),
+            ...$this->removeParallelizationArguments($arguments),
             '--list-tests',
         ]))->mustRun()->getOutput();
 
@@ -94,6 +94,18 @@ private function allTests(array $arguments): array
         return array_values(array_unique($matches[1]));
     }
 
+    /**
+     * Removes both parallel and processes arguments from the arguments array.
+     * This is useful when running commands that don't support parallel execution.
+     *
+     * @param  array<int, string>  $arguments
+     * @return array<int, string>
+     */
+    private function removeParallelizationArguments(array $arguments): array
+    {
+        return $this->removeProcessesArguments($this->removeParallelArguments($arguments));
+    }
+
     /**
      * @param  array<int, string>  $arguments
      * @return array<int, string>
@@ -103,6 +115,34 @@ private function removeParallelArguments(array $arguments): array
         return array_filter($arguments, fn (string $argument): bool => ! in_array($argument, ['--parallel', '-p'], strict: true));
     }
 
+    /**
+     * @param  array<int, string>  $arguments
+     * @return array<int, string>
+     */
+    private function removeProcessesArguments(array $arguments): array
+    {
+        return array_values(array_filter($arguments, function (string $argument) {
+            if (str_starts_with($argument, '--processes') && str_contains($argument, '=')) {
+                return false;
+            }
+
+            static $skipNext = false;
+            if ($skipNext) {
+                $skipNext = false;
+
+                return false;
+            }
+
+            if ($argument === '--processes') {
+                $skipNext = true;
+
+                return false;
+            }
+
+            return true;
+        }));
+    }
+
     /**
      * Builds the filter argument for the given tests to run.
      */
diff --git a/tests/Unit/Plugins/Shard.php b/tests/Unit/Plugins/Shard.php
new file mode 100644
index 000000000..911658f34
--- /dev/null
+++ b/tests/Unit/Plugins/Shard.php
@@ -0,0 +1,76 @@
+<?php
+
+use Pest\Plugins\Shard;
+use Symfony\Component\Console\Output\BufferedOutput;
+
+it('processes arguments with sharding and removes parallel options from subprocess', function () {
+    $output = new BufferedOutput;
+    $shard = new Shard($output);
+
+    // Use reflection to test the private removeParallelizationArguments method
+    $reflection = new ReflectionClass($shard);
+    $method = $reflection->getMethod('removeParallelizationArguments');
+    $method->setAccessible(true);
+
+    $arguments = [
+        'php',
+        'bin/pest',
+        '--processes=12',
+        '--parallel',
+        '--shard=1/4',
+        '--verbose',
+    ];
+
+    $result = $method->invoke($shard, $arguments);
+
+    expect($result)->toBe(['php', 'bin/pest', '--shard=1/4', '--verbose'])
+        ->and($result)->not->toContain('--processes=12')
+        ->and($result)->not->toContain('--parallel');
+});
+
+it('removes space-separated processes arguments', function () {
+    $output = new BufferedOutput;
+    $shard = new Shard($output);
+
+    $reflection = new ReflectionClass($shard);
+    $method = $reflection->getMethod('removeParallelizationArguments');
+    $method->setAccessible(true);
+
+    $arguments = [
+        'php',
+        'bin/pest',
+        '--processes',
+        '8',
+        '--parallel',
+        '--other-flag',
+    ];
+
+    $result = $method->invoke($shard, $arguments);
+
+    expect($result)->toBe(['php', 'bin/pest', '--other-flag'])
+        ->and($result)->not->toContain('--processes')
+        ->and($result)->not->toContain('8')
+        ->and($result)->not->toContain('--parallel');
+});
+
+it('preserves non-parallel arguments when filtering', function () {
+    $output = new BufferedOutput;
+    $shard = new Shard($output);
+
+    $reflection = new ReflectionClass($shard);
+    $method = $reflection->getMethod('removeParallelizationArguments');
+    $method->setAccessible(true);
+
+    $arguments = [
+        'php',
+        'bin/pest',
+        '--filter',
+        'UserTest',
+        '--verbose',
+        '--stop-on-failure',
+    ];
+
+    $result = $method->invoke($shard, $arguments);
+
+    expect($result)->toBe($arguments); // Should be unchanged
+});
diff --git a/tests/Visual/Shard.php b/tests/Visual/Shard.php
new file mode 100644
index 000000000..6d01266d3
--- /dev/null
+++ b/tests/Visual/Shard.php
@@ -0,0 +1,48 @@
+<?php
+
+use Symfony\Component\Process\Process;
+
+test('shard works with processes option - fixes bug #1454', function () {
+    $process = new Process([
+        'php',
+        'bin/pest',
+        '--processes=4',
+        '--shard=1/2',
+        '--parallel',
+        'tests/Fixtures/ExampleTest.php',
+    ], dirname(__DIR__, 2), [
+        'COLLISION_PRINTER' => 'DefaultPrinter',
+        'COLLISION_IGNORE_DURATION' => 'true',
+    ]);
+
+    $process->run();
+
+    expect($process->getExitCode())->toBe(0)
+        ->and($process->getOutput())
+        ->not->toContain('Unknown option "--processes"')
+        ->toContain('Tests:')
+        ->toContain('Shard:');
+})->skipOnWindows();
+
+test('shard removes processes from list-tests subprocess call', function () {
+    // This test verifies that --processes doesn't get passed to the --list-tests call
+    $process = new Process([
+        'php',
+        'bin/pest',
+        '--processes=2',
+        '--shard=1/1',
+        '--parallel',
+        'tests/Fixtures/ExampleTest.php',
+    ], dirname(__DIR__, 2), [
+        'COLLISION_PRINTER' => 'DefaultPrinter',
+        'COLLISION_IGNORE_DURATION' => 'true',
+    ]);
+
+    $process->run();
+
+    expect($process->getExitCode())->toBe(0)
+        ->and($process->getOutput())
+        ->not->toContain('Unknown option "--processes"')
+        ->not->toContain('The "--processes" option requires a value')
+        ->toContain('Shard:'); // Just check that shard output exists, don't be too specific
+})->skipOnWindows();