diff --git a/public/index.php b/public/index.php
index 67c75d8..2da4f07 100644
--- a/public/index.php
+++ b/public/index.php
@@ -28,28 +28,28 @@
       $minuend - $subtrahend
     : false);
   }
-  $hinamizawa_total = disk_total_space(/data/);
-  $hinamizawa_free = disk_free_space(/data/);
+  $hinamizawa_total = disk_total_space("/data/");
+  $hinamizawa_free = disk_free_space("/data/");
   $hinamizawa_used = getDifference($hinamizawa_total, $hinamizawa_free);
   $hinamizawa_percent = 
     getPercentageUsed($hinamizawa_total, $hinamizawa_used);
-  $maebara_total = disk_total_space(/data/maebara/);
-  $maebara_free = disk_free_space(/data/maebara/);
+  $maebara_total = disk_total_space("/data/maebara/");
+  $maebara_free = disk_free_space("/data/maebara/");
   $maebara_used = getDifference($maebara_total, $maebara_free);
   $maebara_percent = 
     getPercentageUsed($maebara_total, $maebara_used);
-  $houjou_total = disk_total_space(/data/houjou/);
-  $houjou_free = disk_free_space(/data/houjou/);
+  $houjou_total = disk_total_space("/data/houjou/");
+  $houjou_free = disk_free_space("/data/houjou/");
   $houjou_used = getDifference($houjou_total, $houjou_free);
   $houjou_percent = 
     getPercentageUsed($houjou_total, $houjou_used);
-  $ryuuguu_total = disk_total_space(/data/ryuuguu/);
-  $ryuuguu_free = disk_free_space(/data/ryuuguu/);
+  $ryuuguu_total = disk_total_space("/data/ryuuguu/");
+  $ryuuguu_free = disk_free_space("/data/ryuuguu/");
   $ryuuguu_used = getDifference($ryuuguu_total, $ryuuguu_free);
   $ryuuguu_percent = 
     getPercentageUsed($ryuuguu_total, $ryuuguu_used);
-  $sonozaki_total = disk_total_space(/data/sonozaki/);
-  $sonozaki_free = disk_free_space(/data/sonozaki/);
+  $sonozaki_total = disk_total_space("/data/sonozaki/");
+  $sonozaki_free = disk_free_space("/data/sonozaki/");
   $sonozaki_used = getDifference($sonozaki_total, $sonozaki_free);
   $sonozaki_percent = 
     getPercentageUsed($sonozaki_total, $sonozaki_used);