diff --git a/lib/puppet-lint/plugins/check_unsafe_interpolations.rb b/lib/puppet-lint/plugins/check_unsafe_interpolations.rb
index 33838f1..480493c 100644
--- a/lib/puppet-lint/plugins/check_unsafe_interpolations.rb
+++ b/lib/puppet-lint/plugins/check_unsafe_interpolations.rb
@@ -33,7 +33,7 @@ def check_unsafe_title(title)
   def check_unsafe_interpolations(command_resources)
     command_resources[:tokens].each do |token|
       # Skip iteration if token isn't a command of type :NAME
-      next unless COMMANDS.include?(token.value) && token.type == :NAME
+      next unless COMMANDS.include?(token.value) && (token.type == :NAME || token.type == :UNLESS)
       # Don't check the command if it is parameterised
       next if parameterised?(token)