diff --git a/bitcoinrb.gemspec b/bitcoinrb.gemspec
index a20f323..ec896ab 100644
--- a/bitcoinrb.gemspec
+++ b/bitcoinrb.gemspec
@@ -20,7 +20,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency 'ecdsa_ext', '~> 0.5.0'
+  spec.add_runtime_dependency 'ecdsa_ext', '~> 0.5.1'
   spec.add_runtime_dependency 'eventmachine'
   spec.add_runtime_dependency 'murmurhash3', '~> 0.1.7'
   spec.add_runtime_dependency 'bech32', '>= 1.3.0'
diff --git a/lib/bitcoin/ext/ecdsa.rb b/lib/bitcoin/ext/ecdsa.rb
index c61cf6b..776ebd8 100644
--- a/lib/bitcoin/ext/ecdsa.rb
+++ b/lib/bitcoin/ext/ecdsa.rb
@@ -10,12 +10,6 @@ def ==(other)
   end
 end
 
-class ::ECDSA::Point
-  def to_hex(compression = true)
-    ECDSA::Format::PointOctetString.encode(self, compression: compression).bth
-  end
-end
-
 module ::ECDSA::Format::PointOctetString
 
   class << self