diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb
index f0b6afc4b4..73fd96f979 100644
--- a/activerecord/lib/active_record/counter_cache.rb
+++ b/activerecord/lib/active_record/counter_cache.rb
@@ -20,7 +20,7 @@ module ActiveRecord
       def reset_counters(id, *counters)
         object = find(id)
         counters.each do |counter_association|
-          has_many_association = _reflect_on_association(counter_association.to_sym)
+          has_many_association = _reflect_on_association(counter_association)
           unless has_many_association
             has_many = reflect_on_all_associations(:has_many)
             has_many_association = has_many.find { |association| association.counter_cache_column && association.counter_cache_column.to_sym == counter_association.to_sym }
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 90e99957f6..eaaa409636 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -19,15 +19,15 @@ module ActiveRecord
     #
     #   Person.group(:city).count
     #   # => { 'Rome' => 5, 'Paris' => 3 }
-    # 
-    # If +count+ is used with +group+ for multiple columns, it returns a Hash whose 
-    # keys are an array containing the individual values of each column and the value 
+    #
+    # If +count+ is used with +group+ for multiple columns, it returns a Hash whose
+    # keys are an array containing the individual values of each column and the value
     # of each key would be the +count+.
-    # 
+    #
     #   Article.group(:status, :category).count
-    #   # =>  {["draft", "business"]=>10, ["draft", "technology"]=>4, 
+    #   # =>  {["draft", "business"]=>10, ["draft", "technology"]=>4,
     #          ["published", "business"]=>0, ["published", "technology"]=>2}
-    # 
+    #
     # If +count+ is used with +select+, it will count the selected columns:
     #
     #   Person.select(:age).count
@@ -274,7 +274,7 @@ module ActiveRecord
       group_attrs = group_values
 
       if group_attrs.first.respond_to?(:to_sym)
-        association  = @klass._reflect_on_association(group_attrs.first.to_sym)
+        association  = @klass._reflect_on_association(group_attrs.first)
         associated   = group_attrs.size == 1 && association && association.belongs_to? # only count belongs_to associations
         group_fields = Array(associated ? association.foreign_key : group_attrs)
       else
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index eff5c8f09c..3df0df40ee 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -26,7 +26,7 @@ module ActiveRecord
             queries << '1=0'
           else
             table       = Arel::Table.new(column, default_table.engine)
-            association = klass._reflect_on_association(column.to_sym)
+            association = klass._reflect_on_association(column)
 
             value.each do |k, v|
               queries.concat expand(association && association.klass, table, k, v)
@@ -55,7 +55,7 @@ module ActiveRecord
       #
       # For polymorphic relationships, find the foreign key and type:
       # PriceEstimate.where(estimate_of: treasure)
-      if klass && reflection = klass._reflect_on_association(column.to_sym)
+      if klass && reflection = klass._reflect_on_association(column)
         if reflection.polymorphic? && base_class = polymorphic_base_class_from_value(value)
           queries << build(table[reflection.foreign_type], base_class)
         end