diff --git a/lib/bson/binary.rb b/lib/bson/binary.rb
index f4f4d2ed4..e3fc78c27 100644
--- a/lib/bson/binary.rb
+++ b/lib/bson/binary.rb
@@ -455,7 +455,7 @@ def self.extract_args_for_vector(vector, dtype, padding)
     # Validate the arguments for a binary vector.
     # @param [ Array ] data The vector data.
     # @param [ ::Symbol ] dtype The vector data type.
-    # @param [ Integer | nil ] padding The padding. Must be 0 if vector is a BSON::Vector.
+    # @param [ Integer ] padding The padding. Must be 0 if vector is a BSON::Vector.
     # @raise [ ArgumentError ] If the arguments are invalid.
     def self.validate_args_for_vector!(data, dtype, padding)
       raise ArgumentError, "Unknown dtype #{dtype}" unless VECTOR_DATA_TYPES.key?(dtype)
diff --git a/lib/bson/vector.rb b/lib/bson/vector.rb
index bdec582eb..5d442a023 100644
--- a/lib/bson/vector.rb
+++ b/lib/bson/vector.rb
@@ -35,7 +35,7 @@ def data
     # @param [ Integer ] padding The number of bits in the final byte that are to
     # be ignored when a vector element's size is less than a byte
     # and the length of the vector is not a multiple of 8.
-    def initialize(data, dtype, padding)
+    def initialize(data, dtype, padding = 0)
       @dtype = dtype
       @padding = padding
       super(data.dup)
diff --git a/spec/bson/vector_spec.rb b/spec/bson/vector_spec.rb
new file mode 100644
index 000000000..cfb43b517
--- /dev/null
+++ b/spec/bson/vector_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Copyright (C) 2025-present MongoDB Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'spec_helper'
+
+describe BSON::Vector do
+  it 'behaves like an Array' do
+    expect(described_class.new([ 1, 2, 3 ], :int8)).to be_a(Array)
+  end
+
+  describe '#initialize' do
+    context 'when padding is not provided' do
+      let(:vector) { described_class.new([ 1, 2, 3 ], :int8) }
+
+      it 'sets the padding to 0' do
+        expect(vector.padding).to eq(0)
+      end
+    end
+  end
+end