diff --git a/src/Cli/Cli.php b/src/Cli/Cli.php
index dfa54fd..25d4133 100644
--- a/src/Cli/Cli.php
+++ b/src/Cli/Cli.php
@@ -67,7 +67,7 @@ function usage(string $name, Input\InputCollection $collection): string
                     : $a->name()
             );
         }
-        $arguments = trim(implode($arguments, ' '));
+        $arguments = trim(implode(' ', $arguments));
 
         return sprintf(
             'Usage: %s [OPTIONS]... %s%s',