diff --git a/lib/web_push.rb b/lib/web_push.rb
index 80ccaf6..93d1e13 100644
--- a/lib/web_push.rb
+++ b/lib/web_push.rb
@@ -56,10 +56,6 @@ def encode64(bytes)
     end
 
     def decode64(str)
-      # For Ruby < 2.3, Base64.urlsafe_decode64 strict decodes and will raise errors if encoded value is not properly padded
-      # Implementation: http://ruby-doc.org/stdlib-2.3.0/libdoc/base64/rdoc/Base64.html#method-i-urlsafe_decode64
-      str = str.ljust((str.length + 3) & ~3, '=') if !str.end_with?('=') && str.length % 4 != 0
-
       Base64.urlsafe_decode64(str)
     end
 
diff --git a/spec/web_push_spec.rb b/spec/web_push_spec.rb
index 42d806c..f915b61 100644
--- a/spec/web_push_spec.rb
+++ b/spec/web_push_spec.rb
@@ -5,6 +5,18 @@
     expect(WebPush::VERSION).not_to be nil
   end
 
+  describe '.decode64' do
+    let(:a_padded_key) { "YWJjZGU=" }
+
+    it 'urlsafe decodes padded base64 string' do
+      expect(WebPush.decode64(a_padded_key)).to eq("abcde")
+    end
+
+    it 'urlsafe decodes unpadded base64 string' do
+      expect(WebPush.decode64(a_padded_key.delete("="))).to eq("abcde")
+    end
+  end
+
   shared_examples 'web push protocol standard error handling' do
     it 'raises InvalidSubscription if the API returns a 404 Error' do
       stub_request(:post, expected_endpoint)