diff --git a/share/linters/.rubocop.yml b/share/linters/.rubocop.yml
index 639c779a11..f2c290aba0 100644
--- a/share/linters/.rubocop.yml
+++ b/share/linters/.rubocop.yml
@@ -730,6 +730,9 @@ Style/LineEndConcatenation:
 Style/MultilineIfModifier:
   Enabled: False
 
+Style/UnpackFirst:
+  Enabled: False
+
 ######
 # LINT
 ######
diff --git a/src/vmm_mad/exec/one_vmm_exec.rb b/src/vmm_mad/exec/one_vmm_exec.rb
index a6adcdd009..1ac5698d2c 100755
--- a/src/vmm_mad/exec/one_vmm_exec.rb
+++ b/src/vmm_mad/exec/one_vmm_exec.rb
@@ -697,7 +697,7 @@ class ExecDriver < VirtualMachineDriver
         target_xpath = "VM/TEMPLATE/DISK[ATTACH='YES']/TARGET"
         target = ensure_xpath(xml_data, id, action, target_xpath) || return
 
-        target_index = target.downcase[-1..-1].unpack1('c') - 97
+        target_index = target.downcase[-1..-1].unpack('c').first - 97
 
         action = VmmAction.new(self, id, :attach_disk, drv_message)
 
@@ -744,7 +744,7 @@ class ExecDriver < VirtualMachineDriver
         target_xpath = "VM/TEMPLATE/DISK[ATTACH='YES']/TARGET"
         target = ensure_xpath(xml_data, id, action, target_xpath) || return
 
-        target_index = target.downcase[-1..-1].unpack1('c') - 97
+        target_index = target.downcase[-1..-1].unpack('c').first - 97
 
         action = VmmAction.new(self, id, :detach_disk, drv_message)
 
@@ -1361,7 +1361,7 @@ end
 #
 ################################################################################
 
-ENV_CONF = Hash.new("").merge!(ENV)
+ENV_CONF = Hash.new('').merge!(ENV)
 LIVE_DISK_SNAPSHOTS = ENV_CONF['LIVE_DISK_SNAPSHOTS'].split
 VNMAD_LOCAL_ACTIONS = ENV_CONF['VNMAD_LOCAL_ACTIONS'].split