diff --git a/CHANGELOG.md b/CHANGELOG.md
index db575cf..07243c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.11.17 - September 17, 2018
+
+- Do not crash when given too short account numbers for New Zealand
+
 ## 0.11.16 - September 3, 2018
 
 - Loosen `i18n` dependency (thanks @glaszig!)
diff --git a/lib/ibandit/local_details_cleaner.rb b/lib/ibandit/local_details_cleaner.rb
index 0e8a436..929bada 100644
--- a/lib/ibandit/local_details_cleaner.rb
+++ b/lib/ibandit/local_details_cleaner.rb
@@ -455,7 +455,7 @@ def self.clean_nz_details(local_details)
         account_number = cleaned_account_number[6..-1]
       end
 
-      if account_number.length == 9
+      if account_number && account_number.length == 9
         # > Some banks (such as BNZ) include three digits of the suffix in their
         # > presentation of the account number to the end customer. Other banks
         # > only show the last two digits of the suffix to the end customer.
diff --git a/lib/ibandit/version.rb b/lib/ibandit/version.rb
index c2b1fa5..ec1bf54 100644
--- a/lib/ibandit/version.rb
+++ b/lib/ibandit/version.rb
@@ -1,3 +1,3 @@
 module Ibandit
-  VERSION = "0.11.16".freeze
+  VERSION = "0.11.17".freeze
 end
diff --git a/spec/ibandit/local_details_cleaner_spec.rb b/spec/ibandit/local_details_cleaner_spec.rb
index e84d600..c0caeda 100644
--- a/spec/ibandit/local_details_cleaner_spec.rb
+++ b/spec/ibandit/local_details_cleaner_spec.rb
@@ -956,6 +956,11 @@
         its([:branch_code]) { is_expected.to eq("2222") }
         its([:account_number]) { is_expected.to eq("3333333044") }
       end
+
+      context "when the account number is shorter than 6 chars" do
+        let(:account_number) { "12345" }
+        its([:account_number]) { is_expected.to be_nil }
+      end
     end
 
     context "without an account number" do