diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6283946..32ec317 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,12 +2,16 @@
 
 This file tracks all the changes (https://keepachangelog.com/en/1.0.0/) made to the client. This allows parsers such as Dependabot to provide a clean overview in pull requests.
 
-## [v0.9.2] - 2020-07-06
+## [v0.9.2] - 2020-07-07
 
 #### Added
 
 - Quotation, Invoice and DistributeTax payloads now accept a `:tax_only_adjustment` param to make tax adjustments that need not be correlated with a total cost adjustment
 
+#### Changed
+
+- Fix a bug with fallback quotation responses where an empty set of line items would raise `ArgumentError`
+
 ## [v0.9.1] - 2020-03-24
 
 #### Added
diff --git a/lib/vertex_client/responses/quotation_fallback.rb b/lib/vertex_client/responses/quotation_fallback.rb
index 5cb0e17..0b96107 100644
--- a/lib/vertex_client/responses/quotation_fallback.rb
+++ b/lib/vertex_client/responses/quotation_fallback.rb
@@ -11,7 +11,7 @@ def subtotal
       end
 
       def total_tax
-        @total_tax ||= line_items.sum(&:total_tax).round(2, :half_even)
+        @total_tax ||= line_items.sum(&:total_tax).to_d.round(2, :half_even)
       end
 
       def total
diff --git a/test/responses/quotation_fallback_test.rb b/test/responses/quotation_fallback_test.rb
index 219f355..5bf966a 100644
--- a/test/responses/quotation_fallback_test.rb
+++ b/test/responses/quotation_fallback_test.rb
@@ -18,6 +18,11 @@
     it 'is the sum of price from line_items' do
       assert_equal 135.5, response.subtotal.to_f
     end
+
+    it 'handles empty quotes' do
+      working_quote_params[:line_items] = []
+      assert_equal 0.0, response.subtotal.to_f
+    end
   end
 
   describe 'total_tax' do
@@ -25,6 +30,11 @@
       it 'is the sum of total_tax from line_items' do
         assert_equal 8.66, response.total_tax.to_f
       end
+
+      it 'handles empty quotes' do
+        working_quote_params[:line_items] = []
+        assert_equal 0.0, response.total_tax.to_f
+      end
     end
 
     describe 'for EU customer' do