diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 1ab0d12f05..2566bbdfcc 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -53,11 +53,11 @@ Metrics/AbcSize:
 # Offense count: 2
 # Configuration parameters: CountComments.
 Metrics/ClassLength:
-  Max: 152
+  Max: 155
 
 # Offense count: 12
 Metrics/CyclomaticComplexity:
-  Max: 24
+  Max: 25
 
 # Offense count: 297
 # Configuration parameters: AllowHeredoc, AllowURI, URISchemes.
diff --git a/scripts/download_clean_ingest.rb b/scripts/download_clean_ingest.rb
index 1293502fa8..f197e9e18e 100644
--- a/scripts/download_clean_ingest.rb
+++ b/scripts/download_clean_ingest.rb
@@ -50,6 +50,8 @@ def initialize(argv)
     mode = argv.shift
     args = argv
 
+    unrecognized_flags = args.select { |arg| arg =~ /^-/ }
+    raise("Unrecognized flags: #{unrecognized_flags.join(', ')}") unless unrecognized_flags.empty?
     raise("#{JUST_REINDEX} should only be used with #{IDS} or #{QUERY} modes") if @is_just_reindex && ![IDS, ID_FILES, QUERY].include?(mode)
 
     log_init(orig)
diff --git a/spec/scripts/download_clean_ingest_spec.rb b/spec/scripts/download_clean_ingest_spec.rb
index 4924206d6a..8d9a0c5a9e 100644
--- a/spec/scripts/download_clean_ingest_spec.rb
+++ b/spec/scripts/download_clean_ingest_spec.rb
@@ -46,6 +46,9 @@ def dci_output(*args)
     "--just-reindex #{default_flags} #{default_mode}" => [
       /should only be used with/
     ],
+    '--this-is-not-valid -neither-is-this' => [
+      /Unrecognized flags: --this-is-not-valid, -neither-is-this/
+    ],
 
     # Modes expected to succeed:
     # (--back can be slow)