diff --git a/spec/jwt/jwa/ps_spec.rb b/spec/jwt/jwa/ps_spec.rb
new file mode 100644
index 00000000..53b57433
--- /dev/null
+++ b/spec/jwt/jwa/ps_spec.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+RSpec.describe JWT::JWA::Ps do
+  let(:rsa_key) { OpenSSL::PKey::RSA.generate(2048) }
+  let(:data) { 'test data' }
+  let(:ps256_instance) { described_class.new('PS256') }
+  let(:ps384_instance) { described_class.new('PS384') }
+  let(:ps512_instance) { described_class.new('PS512') }
+
+  describe '#initialize' do
+    it 'initializes with the correct algorithm and digest' do
+      expect(ps256_instance.instance_variable_get(:@alg)).to eq('PS256')
+      expect(ps256_instance.send(:digest_algorithm)).to eq('sha256')
+
+      expect(ps384_instance.instance_variable_get(:@alg)).to eq('PS384')
+      expect(ps384_instance.send(:digest_algorithm)).to eq('sha384')
+
+      expect(ps512_instance.instance_variable_get(:@alg)).to eq('PS512')
+      expect(ps512_instance.send(:digest_algorithm)).to eq('sha512')
+    end
+  end
+
+  describe '#sign' do
+    context 'with a valid RSA key' do
+      it 'signs the data with PS256' do
+        expect(ps256_instance.sign(data: data, signing_key: rsa_key)).not_to be_nil
+      end
+
+      it 'signs the data with PS384' do
+        expect(ps384_instance.sign(data: data, signing_key: rsa_key)).not_to be_nil
+      end
+
+      it 'signs the data with PS512' do
+        expect(ps512_instance.sign(data: data, signing_key: rsa_key)).not_to be_nil
+      end
+    end
+
+    context 'with an invalid key' do
+      it 'raises an error' do
+        expect do
+          ps256_instance.sign(data: data, signing_key: 'invalid_key')
+        end.to raise_error(JWT::EncodeError, /The given key is a String. It has to be an OpenSSL::PKey::RSA instance./)
+      end
+    end
+  end
+
+  describe '#verify' do
+    let(:ps256_signature) { ps256_instance.sign(data: data, signing_key: rsa_key) }
+    let(:ps384_signature) { ps384_instance.sign(data: data, signing_key: rsa_key) }
+    let(:ps512_signature) { ps512_instance.sign(data: data, signing_key: rsa_key) }
+
+    context 'with a valid RSA key' do
+      it 'verifies the signature with PS256' do
+        expect(ps256_instance.verify(data: data, signature: ps256_signature, verification_key: rsa_key)).to be(true)
+      end
+
+      it 'verifies the signature with PS384' do
+        expect(ps384_instance.verify(data: data, signature: ps384_signature, verification_key: rsa_key)).to be(true)
+      end
+
+      it 'verifies the signature with PS512' do
+        expect(ps512_instance.verify(data: data, signature: ps512_signature, verification_key: rsa_key)).to be(true)
+      end
+    end
+
+    context 'with an invalid signature' do
+      it 'raises a verification error' do
+        expect(ps256_instance.verify(data: data, signature: 'invalid_signature', verification_key: rsa_key)).to be(false)
+      end
+    end
+  end
+end
diff --git a/spec/jwt/jwa/rsa_spec.rb b/spec/jwt/jwa/rsa_spec.rb
index 6bea9ba2..ea73c93d 100644
--- a/spec/jwt/jwa/rsa_spec.rb
+++ b/spec/jwt/jwa/rsa_spec.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
-
 RSpec.describe JWT::JWA::Rsa do
   let(:rsa_key) { OpenSSL::PKey::RSA.generate(2048) }
   let(:data) { 'test data' }