diff --git a/src/Commands/SecurityReviewCommands.php b/src/Commands/SecurityReviewCommands.php
index c462bff..83d8e1f 100644
--- a/src/Commands/SecurityReviewCommands.php
+++ b/src/Commands/SecurityReviewCommands.php
@@ -72,8 +72,8 @@ class SecurityReviewCommands extends DrushCommands {
       'store' => FALSE,
       'log' => FALSE,
       'lastrun' => FALSE,
-      'check' => [],
-      'skip' => [],
+      'check' => NULL,
+      'skip' => NULL,
       'short' => FALSE,
       'results' => FALSE,
     ]
@@ -108,7 +108,7 @@ class SecurityReviewCommands extends DrushCommands {
       // Fill the $checks array.
       if (!empty($run_checks)) {
         // Get explicitly specified checks.
-        foreach ($run_checks as $check) {
+        foreach (explode(',', $run_checks) as $check) {
           $checks[] = $this->getCheck($check);
         }
       }
@@ -119,7 +119,7 @@ class SecurityReviewCommands extends DrushCommands {
 
       // Mark checks listed after --skip for removal.
       if (!empty($skip_checks)) {
-        foreach ($skip_checks as $skip_check) {
+        foreach (explode(',', $skip_checks) as $skip_check) {
           $to_skip[] = $this->getCheck($skip_check);
         }
       }