diff --git a/test/integration/standard_filter_test.rb b/test/integration/standard_filter_test.rb
index b7374ea31..dd15ff4e9 100644
--- a/test/integration/standard_filter_test.rb
+++ b/test/integration/standard_filter_test.rb
@@ -928,45 +928,58 @@ def test_where_no_target_value
     assert_equal([{ "foo" => true }, { "foo" => "for sure" }], @filters.where(input, "foo"))
   end
 
-  def test_sum
+  def test_sum_with_all_numbers
     input = [1, 2]
+
     assert_equal(3, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
   end
 
   def test_sum_with_numeric_strings
-    input = [1, "2"]
-    assert_equal(3, @filters.sum(input))
+    input = [1, 2, "3", "4"]
+
+    assert_equal(10, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
   end
 
-  def test_sum_with_non_numeric_values
-    input = [3, "foo", { "foo" => "bar" }, true, nil]
-    assert_equal(3, @filters.sum(input))
+  def test_sum_with_nested_arrays
+    input = [1, [2, [3, 4]]]
+
+    assert_equal(10, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
   end
 
-  def test_sum_with_property_on_indexable_map_values
-    input = [
-      { "quantity" => 1 },
-      { "quantity" => 2 },
-    ]
+  def test_sum_with_indexable_map_values
+    input = [{ "quantity" => 1 }, { "quantity" => 2, "weight" => 3 }, { "weight" => 4 }]
 
+    assert_equal(0, @filters.sum(input))
     assert_equal(3, @filters.sum(input, "quantity"))
-    assert_equal(0, @filters.sum(input, "weight"))
+    assert_equal(7, @filters.sum(input, "weight"))
+    assert_equal(0, @filters.sum(input, "subtotal"))
   end
 
-  def test_sum_with_property_on_indexable_non_map_values
-    input = [1, "foo", { "quantity" => 2 }]
+  def test_sum_with_indexable_non_map_values
+    input = [1, [2], "foo", { "quantity" => 3 }]
 
+    assert_equal(3, @filters.sum(input))
     assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
       @filters.sum(input, "quantity")
     end
   end
 
-  def test_sum_with_property_on_unindexable_values
-    input = [true, nil, :foo]
-    assert_equal(0, @filters.sum(input, "quantity"))
+  def test_sum_with_unindexable_values
+    input = [1, true, nil, { "quantity" => 2 }]
 
-    mixed_input = [true, nil, :foo, { "quantity" => 3 }]
-    assert_equal(3, @filters.sum(mixed_input, "quantity"))
+    assert_equal(1, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
   end
 
   private