3 files changed, 11 insertions, 9 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 07d41b1c18..7b441bcdb2 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Do not allow passing the column name to `sum` when a block is passed.
+
+    *Rafael Mendonça França*
+
 *   Do not allow passing the column name to `count` when a block is passed.
 
     *Rafael Mendonça França*
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 40bae89170..cef31bea94 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -84,15 +84,13 @@ module ActiveRecord
     def sum(column_name = nil)
       if block_given?
         unless column_name.nil?
-          ActiveSupport::Deprecation.warn \
-            "When `sum' is called with a block, it ignores other arguments. " \
-            "This behavior is now deprecated and will result in an ArgumentError in Rails 6.0."
+          raise ArgumentError, "Column name argument is not supported when a block is passed."
         end
 
-        return super()
+        super()
+      else
+        calculate(:sum, column_name)
       end
-
-      calculate(:sum, column_name)
     end
 
     # This calculates aggregate values in the given column. Methods for #count, #sum, #average,
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 5075fed114..7af26d8ff5 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -923,9 +923,9 @@ class CalculationsTest < ActiveRecord::TestCase
     end
   end
 
-  def test_deprecate_sum_with_block_and_column_name
-    assert_deprecated do
-      assert_equal 6, Account.sum(:firm_id) { 1 }
+  def test_sum_with_block_and_column_name_raises_an_error
+    assert_raises(ArgumentError) do
+      Account.sum(:firm_id) { 1 }
     end
   end