diff --git a/src/onedb/fsck.rb b/src/onedb/fsck.rb
index acc8cc5ea0..d9edf1c6c1 100644
--- a/src/onedb/fsck.rb
+++ b/src/onedb/fsck.rb
@@ -527,7 +527,7 @@ EOT
     end
 
     def mac_s_to_i(mac)
-        return nil if mac.empty?
+        return nil if mac.nil? || mac.empty?
         return mac.split(":").map {|e|
             e.to_i(16).to_s(16).rjust(2,"0")}.join("").to_i(16)
     end
diff --git a/src/onedb/fsck/network.rb b/src/onedb/fsck/network.rb
index 659b39c46d..346c1bf56a 100644
--- a/src/onedb/fsck/network.rb
+++ b/src/onedb/fsck/network.rb
@@ -391,6 +391,8 @@ module OneDBFsck
                 end
 
                 counter_ar.each do |mac, counter_lease|
+                    next if mac.nil?
+
                     index = ((mac & 0xFFFFFFFF) - (first_mac & 0xFFFFFFFF) ) % 0x100000000
 
                     new_lease_obj = ""