diff --git a/lib/ckb/types/script.rb b/lib/ckb/types/script.rb
index 2fcb346c..c82639ac 100644
--- a/lib/ckb/types/script.rb
+++ b/lib/ckb/types/script.rb
@@ -15,8 +15,8 @@ def initialize(code_hash:, args:, hash_type: "Data")
 
       # @return [Integer] Byte
       def calculate_bytesize
-        bytesize = 0
-        bytesize = Utils.hex_to_bin(@code_hash).bytesize if @code_hash
+        bytesize = 1
+        bytesize += Utils.hex_to_bin(@code_hash).bytesize if @code_hash
         (@args || []).map { |arg| Utils.hex_to_bin(arg).bytesize }.reduce(bytesize, &:+)
       end
 
diff --git a/spec/ckb/types/output_spec.rb b/spec/ckb/types/output_spec.rb
index 40bf1a43..598a4ee0 100644
--- a/spec/ckb/types/output_spec.rb
+++ b/spec/ckb/types/output_spec.rb
@@ -13,14 +13,14 @@
     it "default" do
       expect(
         output.calculate_bytesize
-      ).to eq 60
+      ).to eq 93
     end
 
     it "with data" do
       output.instance_variable_set(:@data, "0x1234")
       expect(
         output.calculate_bytesize
-      ).to eq 62
+      ).to eq 93
     end
 
     it "with type script" do
@@ -32,13 +32,13 @@
 
       expect(
         output.calculate_bytesize
-      ).to eq 92
+      ).to eq (93 + 33)
     end
   end
 
   it "calculate min capacity" do
     expect(
       output.calculate_min_capacity
-    ).to eq CKB::Utils.byte_to_shannon(60)
+    ).to eq CKB::Utils.byte_to_shannon(93)
   end
 end
diff --git a/spec/ckb/types/script_spec.rb b/spec/ckb/types/script_spec.rb
index a0050feb..833a3020 100644
--- a/spec/ckb/types/script_spec.rb
+++ b/spec/ckb/types/script_spec.rb
@@ -1,7 +1,7 @@
 RSpec.describe CKB::Types::Script do
   let(:script) do
     code_hash = CKB::Blake2b.hexdigest(
-      Utils.hex_to_bin(
+      CKB::Utils.hex_to_bin(
         "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"
       )
     )
@@ -29,7 +29,7 @@
         args: args
       )
     end
-    let(:min_capacity) { 52 }
+    let(:min_capacity) { 53 }
 
     it "success" do
       expect(