diff --git a/includes/shell/Command.php b/includes/shell/Command.php
index d6f95783f0d..d9fa82dfa3e 100644
--- a/includes/shell/Command.php
+++ b/includes/shell/Command.php
@@ -463,6 +463,12 @@ class Command {
 				$isWrite = array_key_exists( $fd, $readPipes );
 
 				if ( $isWrite ) {
+					// Don't bother writing if the buffer is empty
+					if ( $buffers[$fd] === '' ) {
+						fclose( $pipes[$fd] );
+						unset( $pipes[$fd] );
+						continue;
+					}
 					$res = fwrite( $pipe, $buffers[$fd], 65536 );
 				} else {
 					$res = fread( $pipe, 65536 );
diff --git a/tests/phpunit/includes/shell/CommandTest.php b/tests/phpunit/includes/shell/CommandTest.php
index 3862cc24445..2e031638857 100644
--- a/tests/phpunit/includes/shell/CommandTest.php
+++ b/tests/phpunit/includes/shell/CommandTest.php
@@ -170,5 +170,12 @@ class CommandTest extends PHPUnit\Framework\TestCase {
 		$command->input( str_repeat( '!', 1000000 ) );
 		$result = $command->execute();
 		$this->assertSame( 1000000, strlen( $result->getStdout() ) );
+
+		// And try it with empty input
+		$command = new Command();
+		$command->params( 'cat' );
+		$command->input( '' );
+		$result = $command->execute();
+		$this->assertSame( '', $result->getStdout() );
 	}
 }