diff --git a/spec/ameba/rule/performance/count_spec.cr b/spec/ameba/rule/performance/size_after_filter_spec.cr
similarity index 91%
rename from spec/ameba/rule/performance/count_spec.cr
rename to spec/ameba/rule/performance/size_after_filter_spec.cr
index a3f1dbd5..5527c0f3 100644
--- a/spec/ameba/rule/performance/count_spec.cr
+++ b/spec/ameba/rule/performance/size_after_filter_spec.cr
@@ -1,9 +1,9 @@
 require "../../../spec_helper"
 
 module Ameba::Rule::Performance
-  subject = Count.new
+  subject = SizeAfterFilter.new
 
-  describe Count do
+  describe SizeAfterFilter do
     it "passes if there is no potential performance improvements" do
       source = Source.new %(
         [1, 2, 3].select { |e| e > 2 }
@@ -43,8 +43,8 @@ module Ameba::Rule::Performance
         source = Source.new %(
           [1, 2, 3].reject(&.empty?).size
         )
-        rule = Rule::Performance::Count.new
-        rule.object_call_names = %w(select)
+        rule = Rule::Performance::SizeAfterFilter.new
+        rule.filter_names = %w(select)
         rule.catch(source).should be_valid
       end
     end
diff --git a/src/ameba/rule/performance/count.cr b/src/ameba/rule/performance/size_after_filter.cr
similarity index 62%
rename from src/ameba/rule/performance/count.cr
rename to src/ameba/rule/performance/size_after_filter.cr
index 1e079582..e3035d7b 100644
--- a/src/ameba/rule/performance/count.cr
+++ b/src/ameba/rule/performance/size_after_filter.cr
@@ -1,6 +1,5 @@
 module Ameba::Rule::Performance
-  # This rule is used to identify usage of `size` calls that follow to object
-  # caller names `select` and `reject`.
+  # This rule is used to identify usage of `size` calls that follow filter.
   #
   # For example, this is considered invalid:
   #
@@ -16,20 +15,29 @@ module Ameba::Rule::Performance
   #
   # ```
   # [1, 2, 3].count { |e| e > 2 }
-  # [1, 2, 3].count { |e| e > 2 }
+  # [1, 2, 3].count { |e| e >= 2 }
   # [1, 2, 3].count(&.< 2)
   # [0, 1, 2].count(&.zero?)
   # [0, 1, 2].count(&.!= 0)
   # ```
   #
-  struct Count < Base
-    SIZE_CALL_NAME = "size"
-    MSG = "Use `count {...}` instead of `%s {...}.#{SIZE_CALL_NAME}`."
+  # YAML configuration example:
+  #
+  # ```
+  # Performance/SizeAfterFilter:
+  #   Enabled: true
+  #   FilterNames:
+  #     - select
+  #     - reject
+  # ```
+  #
+  struct SizeAfterFilter < Base
+    SIZE_NAME = "size"
+    MSG = "Use `count {...}` instead of `%s {...}.#{SIZE_NAME}`."
 
     properties do
-      object_call_names : Array(String) = %w(select reject)
-      description "Identifies usage of `size` calls that follow to object \
-                   caller names (`select`/`reject` by default)."
+      filter_names : Array(String) = %w(select reject)
+      description "Identifies usage of `size` calls that follow filter"
     end
 
     def test(source)
@@ -37,10 +45,10 @@ module Ameba::Rule::Performance
     end
 
     def test(source, node : Crystal::Call)
-      return unless node.name == SIZE_CALL_NAME && (obj = node.obj)
+      return unless node.name == SIZE_NAME && (obj = node.obj)
 
       if obj.is_a?(Crystal::Call) &&
-         object_call_names.includes?(obj.name) && !obj.block.nil?
+         filter_names.includes?(obj.name) && !obj.block.nil?
 
         issue_for obj.name_location, node.name_end_location, MSG % obj.name
       end