diff --git a/lib/fasterer/method_call.rb b/lib/fasterer/method_call.rb
index be8e420..9d8fbf4 100644
--- a/lib/fasterer/method_call.rb
+++ b/lib/fasterer/method_call.rb
@@ -9,6 +9,10 @@ class MethodCall
 
     alias_method :name, :method_name
 
+    # Defines CONSTANT_TYPES constant with the list of constant
+    # types like String, Nil, Integer, Symbol, Boolean or a Contant
+    PRIMITIVE_DATA_TYPES = %i[nil lit str const true false].freeze
+
     def initialize(element)
       @element = element
       set_call_element
@@ -24,6 +28,10 @@ def has_block?
       @block_present || false
     end
 
+    def has_block_with_primitive_data_types?
+      has_block? && PRIMITIVE_DATA_TYPES.include?(@block_body.first)
+    end
+
     def receiver_element
       call_element[1]
     end
diff --git a/lib/fasterer/offense.rb b/lib/fasterer/offense.rb
index 883b7b1..0a9038f 100644
--- a/lib/fasterer/offense.rb
+++ b/lib/fasterer/offense.rb
@@ -44,7 +44,7 @@ def explanation
         'Enumerable#sort is slower than Enumerable#sort_by',
 
       fetch_with_argument_vs_block:
-        'Hash#fetch with second argument is slower than Hash#fetch with block',
+        'Hash#fetch with block of primitive data types like: String, Integer, Symbol, Boolean or Nil is slower than Hash#fetch with second argument',
 
       keys_each_vs_each_key:
         'Hash#keys.each is slower than Hash#each_key. N.B. Hash#each_key cannot be used if the hash is modified during the each block',
diff --git a/lib/fasterer/scanners/method_call_scanner.rb b/lib/fasterer/scanners/method_call_scanner.rb
index a8f976e..6251c93 100644
--- a/lib/fasterer/scanners/method_call_scanner.rb
+++ b/lib/fasterer/scanners/method_call_scanner.rb
@@ -114,7 +114,7 @@ def check_flatten_offense
     end
 
     def check_fetch_offense
-      if method_call.arguments.count == 2 && !method_call.has_block?
+      if method_call.arguments.count == 1 && method_call.has_block_with_primitive_data_types?
         add_offense(:fetch_with_argument_vs_block)
       end
     end
diff --git a/spec/lib/fasterer/analyzer/14_fetch_with_argument_vs_block_spec.rb b/spec/lib/fasterer/analyzer/14_fetch_with_argument_vs_block_spec.rb
index 18a2fa1..6a8002a 100644
--- a/spec/lib/fasterer/analyzer/14_fetch_with_argument_vs_block_spec.rb
+++ b/spec/lib/fasterer/analyzer/14_fetch_with_argument_vs_block_spec.rb
@@ -6,6 +6,6 @@
   it 'should detect keys fetch with argument once' do
     analyzer = Fasterer::Analyzer.new(test_file_path)
     analyzer.scan
-    expect(analyzer.errors[:fetch_with_argument_vs_block].count).to eq(1)
+    expect(analyzer.errors[:fetch_with_argument_vs_block].count).to eq(4)
   end
 end
diff --git a/spec/support/analyzer/14_fetch_with_argument_vs_block.rb b/spec/support/analyzer/14_fetch_with_argument_vs_block.rb
index 4bc223f..0ee1667 100644
--- a/spec/support/analyzer/14_fetch_with_argument_vs_block.rb
+++ b/spec/support/analyzer/14_fetch_with_argument_vs_block.rb
@@ -1,11 +1,23 @@
 HASH = { :writing => :fast_ruby }
 
 def slow
-  HASH.fetch(:writing, [*1..100])
+  HASH.fetch(:writing) { nil }
+end
+
+def slow
+  HASH.fetch(:writing) { 1 }
+end
+
+def slow
+  HASH.fetch(:writing) { "1" }
+end
+
+def slow
+  HASH.fetch(:writing) { true }
 end
 
 def fast
-  HASH.fetch(:writing) { [*1..100] }
+  HASH.fetch(:writng, 1)
 end
 
 HASH.fetch(:writing)