diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 038c214..a4b5275 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['3.0', '3.1']
+        ruby-version: ['2.7', '3.0', '3.1', '3.2']
     steps:
     - uses: actions/checkout@v3
     - name: Set up Ruby
diff --git a/lib/web_push/encryption.rb b/lib/web_push/encryption.rb
index 2d33f1d..4c6b54e 100644
--- a/lib/web_push/encryption.rb
+++ b/lib/web_push/encryption.rb
@@ -10,8 +10,7 @@ def encrypt(message, p256dh, auth)
       group_name = 'prime256v1'
       salt = Random.new.bytes(16)
 
-      server = OpenSSL::PKey::EC.new(group_name)
-      server.generate_key
+      server = OpenSSL::PKey::EC.generate(group_name)
       server_public_key_bn = server.public_key.to_bn
 
       group = OpenSSL::PKey::EC::Group.new(group_name)
@@ -72,4 +71,4 @@ def blank?(value)
       value.nil? || value.empty?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/web_push/vapid_key.rb b/lib/web_push/vapid_key.rb
index c69f7aa..c9c8959 100644
--- a/lib/web_push/vapid_key.rb
+++ b/lib/web_push/vapid_key.rb
@@ -10,8 +10,7 @@ class VapidKey
     # @return [WebPush::VapidKey] a VapidKey instance for the given public and private keys
     def self.from_keys(public_key, private_key)
       key = new
-      key.public_key = public_key
-      key.private_key = private_key
+      key.set_keys!(public_key, private_key)
 
       key
     end
@@ -20,19 +19,14 @@ def self.from_keys(public_key, private_key)
     #
     # @return [WebPush::VapidKey] a VapidKey instance for the given public and private keys
     def self.from_pem(pem)
-      key = new
-      src = OpenSSL::PKey.read pem
-      key.curve.public_key = src.public_key
-      key.curve.private_key = src.private_key
-
-      key
+      new(OpenSSL::PKey.read pem)
     end
 
     attr_reader :curve
 
-    def initialize
-      @curve = OpenSSL::PKey::EC.new('prime256v1')
-      @curve.generate_key
+    def initialize(pkey = nil)
+      @curve = pkey
+      @curve = OpenSSL::PKey::EC.generate('prime256v1') if @curve.nil?
     end
 
     # Retrieve the encoded elliptic curve public key for VAPID protocol
@@ -57,11 +51,11 @@ def private_key
     end
 
     def public_key=(key)
-      curve.public_key = OpenSSL::PKey::EC::Point.new(group, to_big_num(key))
+      set_keys!(key, nil)
     end
 
     def private_key=(key)
-      curve.private_key = to_big_num(key)
+      set_keys!(nil, key)
     end
 
     def curve_name
@@ -78,7 +72,7 @@ def to_h
     alias to_hash to_h
 
     def to_pem
-      private_key_to_pem + public_key_to_pem
+      curve.to_pem + curve.public_to_pem
     end
 
     def private_key_to_pem
@@ -93,6 +87,32 @@ def inspect
       "#<#{self.class}:#{object_id.to_s(16)} #{to_h.map { |k, v| ":#{k}=#{v}" }.join(' ')}>"
     end
 
+    def set_keys!(public_key = nil, private_key = nil)
+      if public_key.nil?
+        public_key = curve.public_key
+      else
+        public_key = OpenSSL::PKey::EC::Point.new(group, to_big_num(public_key))
+      end
+
+      if private_key.nil?
+        private_key = curve.private_key
+      else
+        private_key = to_big_num(private_key)
+      end
+
+      asn1 = OpenSSL::ASN1::Sequence([
+        OpenSSL::ASN1::Integer.new(1),
+        # Not properly padded but OpenSSL doesn't mind
+        OpenSSL::ASN1::OctetString(private_key.to_s(2)),
+        OpenSSL::ASN1::ObjectId('prime256v1', 0, :EXPLICIT),
+        OpenSSL::ASN1::BitString(public_key.to_octet_string(:uncompressed), 1, :EXPLICIT),
+      ])
+
+      der = asn1.to_der
+
+      @curve = OpenSSL::PKey::EC.new(der)
+    end
+
     private
 
     def to_big_num(key)
diff --git a/spec/web_push/encryption_spec.rb b/spec/web_push/encryption_spec.rb
index 19ee27e..3aed2ac 100644
--- a/spec/web_push/encryption_spec.rb
+++ b/spec/web_push/encryption_spec.rb
@@ -4,9 +4,7 @@
   describe '#encrypt' do
     let(:curve) do
       group = 'prime256v1'
-      curve = OpenSSL::PKey::EC.new(group)
-      curve.generate_key
-      curve
+      OpenSSL::PKey::EC.generate(group)
     end
 
     let(:p256dh) do
diff --git a/web-push.gemspec b/web-push.gemspec
index 4f8e21d..75c9cab 100644
--- a/web-push.gemspec
+++ b/web-push.gemspec
@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
 
   spec.files = `git ls-files`.split("\n")
 
-  spec.required_ruby_version = '>= 3.0'
+  spec.required_ruby_version = '>= 2.7'
 
   spec.add_dependency 'hkdf', '~> 1.0'
   spec.add_dependency 'jwt', '~> 2.0'