diff --git a/modules/auxiliary/client/iec104/iec104.rb b/modules/auxiliary/client/iec104/iec104.rb
index a68444940b..a42cfaf501 100644
--- a/modules/auxiliary/client/iec104/iec104.rb
+++ b/modules/auxiliary/client/iec104/iec104.rb
@@ -87,8 +87,8 @@ class MetasploitModule < Msf::Auxiliary
     apci_data += [asdu_data.size + 4].pack("c") # size byte
     apci_data += String([$tx].pack('v'))
     apci_data += String([$rx].pack('v'))
-	$rx=$rx+2
-	$tx = $tx + 2
+  $rx=$rx+2
+  $tx = $tx + 2
     apci_data += asdu_data
     apci_data
   end