diff --git a/README.md b/README.md
index 938187a..74dce58 100644
--- a/README.md
+++ b/README.md
@@ -112,6 +112,9 @@ The `--help` or `sign --help` option provides more detail about each parameter.
 * `--skip-signed` [short: `-s`, required: no]: If a file is already signed it will be skipped, rather than replacing the existing
 	signature.
 
+* `--append-signature` [short: `-as`, required: no]: If '.exe' or '.dll' file is already signed it will append the signature, just sign otherwise.
+	It has no effect when used with `--skip-signed` or not '.exe' and not '.dll' files.
+
 ### Advanced
 
 * `--page-hashing` [short: `-ph`, required: no]: Causes the Authenticode signing process to generate hashes of pages for verifying when
@@ -148,7 +151,3 @@ a status code according to the complete signing operations.
 ## Requirements
 
 Windows 10 or Windows Server 2016 is required.
-
-## Current Limitations
-
-Dual signing is not supported. This appears to be a limitation of the API used.
diff --git a/src/AzureSign.Core/AuthenticodeKeyVaultSigner.cs b/src/AzureSign.Core/AuthenticodeKeyVaultSigner.cs
index 0a2b0a5..bb94f85 100644
--- a/src/AzureSign.Core/AuthenticodeKeyVaultSigner.cs
+++ b/src/AzureSign.Core/AuthenticodeKeyVaultSigner.cs
@@ -101,17 +101,25 @@ static char[] NullTerminate(ReadOnlySpan<char> str)
 
             if (appendSignature)
             {
-                if (Environment.OSVersion.Version < _win11Version)
+                if (!path.EndsWith(".dll".AsSpan(), StringComparison.InvariantCultureIgnoreCase) &&
+                    !path.EndsWith(".exe".AsSpan(), StringComparison.InvariantCultureIgnoreCase))
                 {
-                    // SignerSignEx3 silently succeeds with append on Windows 10 but does not actually append, so throw an error if we are not on Windows 11 or later.
-                    throw new PlatformNotSupportedException("Appending signatures requires Windows 11 or later.");
+                    logger?.LogWarning("SIG_APPEND is not supported for this file extention and will be ignored.");
                 }
-                if (_timeStampConfiguration.Type == TimeStampType.Authenticode)
+                else
                 {
-                    // E_INVALIDARG is expected from SignerSignEx3, no need to override this error, log warning for troubleshooting
-                    logger?.LogWarning("If you set the dwTimestampFlags parameter to SIGNER_TIMESTAMP_AUTHENTICODE, you cannot set the dwFlags parameter to SIG_APPEND.");
+                    if (Environment.OSVersion.Version < _win11Version)
+                    {
+                        // SignerSignEx3 silently succeeds with append on Windows 10 but does not actually append, so throw an error if we are not on Windows 11 or later.
+                        throw new PlatformNotSupportedException("Appending signatures requires Windows 11 or later.");
+                    }
+                    if (_timeStampConfiguration.Type == TimeStampType.Authenticode)
+                    {
+                        // E_INVALIDARG is expected from SignerSignEx3, no need to override this error, log warning for troubleshooting
+                        logger?.LogWarning("If you set the dwTimestampFlags parameter to SIGNER_TIMESTAMP_AUTHENTICODE, you cannot set the dwFlags parameter to SIG_APPEND.");
+                    }
+                    flags |= SignerSignEx3Flags.SIG_APPEND;
                 }
-                flags |= SignerSignEx3Flags.SIG_APPEND;
             }
 
             SignerSignTimeStampFlags timeStampFlags;
diff --git a/test/AzureSign.Core.Tests/AuthenticodeKeyVaultSignerTests.cs b/test/AzureSign.Core.Tests/AuthenticodeKeyVaultSignerTests.cs
index df5bbb4..aa5d7cf 100644
--- a/test/AzureSign.Core.Tests/AuthenticodeKeyVaultSignerTests.cs
+++ b/test/AzureSign.Core.Tests/AuthenticodeKeyVaultSignerTests.cs
@@ -112,6 +112,84 @@ public void ShouldSignExeWithRSASigningCertificates_Sha256FileDigest_WithTimesta
             }
         }
 
+        [Theory]
+        [MemberData(nameof(RsaCertificates))]
+        public void ShouldSignPS1WithRSASigningCertificates_Sha1FileDigest(string certificate)
+        {
+            var signingCert = new X509Certificate2(certificate, "test", X509KeyStorageFlags.EphemeralKeySet);
+            var signer = new AuthenticodeKeyVaultSigner(signingCert.GetRSAPrivateKey(), signingCert, HashAlgorithmName.SHA1, TimeStampConfiguration.None);
+            var fileToSign = GetPS1FileToSign();
+            var result = signer.SignFile(fileToSign, null, null, null);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: true);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: false);
+            Assert.Equal(0, result);
+        }
+
+        [Theory]
+        [MemberData(nameof(RsaCertificates))]
+        public void ShouldSignPS1WithRSASigningCertificates_Sha256FileDigest(string certificate)
+        {
+            var signingCert = new X509Certificate2(certificate, "test", X509KeyStorageFlags.EphemeralKeySet);
+            var signer = new AuthenticodeKeyVaultSigner(signingCert.GetRSAPrivateKey(), signingCert, HashAlgorithmName.SHA256, TimeStampConfiguration.None);
+            var fileToSign = GetPS1FileToSign();
+            var result = signer.SignFile(fileToSign, null, null, null);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: true);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: false);
+            Assert.Equal(0, result);
+        }
+
+
+        [Theory]
+        [MemberData(nameof(ECDsaCertificates))]
+        public void ShouldSignPS1WithECDsaSigningCertificates_Sha256FileDigest(string certificate)
+        {
+            var signingCert = new X509Certificate2(certificate, "test", X509KeyStorageFlags.EphemeralKeySet);
+            var signer = new AuthenticodeKeyVaultSigner(signingCert.GetECDsaPrivateKey(), signingCert, HashAlgorithmName.SHA256, TimeStampConfiguration.None);
+            var fileToSign = GetPS1FileToSign();
+            var result = signer.SignFile(fileToSign, null, null, null);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: true);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: false);
+            Assert.Equal(0, result);
+        }
+
+        [Theory]
+        [MemberData(nameof(ECDsaCertificates))]
+        public void ShouldSignPS1WithECDsaSigningCertificates_Sha256FileDigest_WithTimestamps(string certificate)
+        {
+            var signingCert = new X509Certificate2(certificate, "test", X509KeyStorageFlags.EphemeralKeySet);
+            var timestampConfig = new TimeStampConfiguration("http://timestamp.digicert.com", HashAlgorithmName.SHA256, TimeStampType.RFC3161);
+            var signer = new AuthenticodeKeyVaultSigner(signingCert.GetECDsaPrivateKey(), signingCert, HashAlgorithmName.SHA256, timestampConfig);
+            var fileToSign = GetPS1FileToSign();
+            var result = signer.SignFile(fileToSign, null, null, null);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: true);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: false);
+            Assert.Equal(0, result);
+        }
+
+
+        [Theory]
+        [MemberData(nameof(RsaCertificates))]
+        public void ShouldSignPS1WithRSASigningCertificates_Sha256FileDigest_WithTimestamps(string certificate)
+        {
+            var signingCert = new X509Certificate2(certificate, "test", X509KeyStorageFlags.EphemeralKeySet);
+            var timestampConfig = new TimeStampConfiguration("http://timestamp.digicert.com", HashAlgorithmName.SHA256, TimeStampType.RFC3161);
+            var signer = new AuthenticodeKeyVaultSigner(signingCert.GetRSAPrivateKey(), signingCert, HashAlgorithmName.SHA256, timestampConfig);
+            var fileToSign = GetPS1FileToSign();
+            var result = signer.SignFile(fileToSign, null, null, null);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: true);
+            Assert.Equal(0, result);
+            result = signer.SignFile(fileToSign, null, null, null, appendSignature: false);
+            Assert.Equal(0, result);
+        }
         private string GetFileToSign()
         {
             var guid = Guid.NewGuid();
@@ -119,6 +197,13 @@ private string GetFileToSign()
             File.Copy("signtarget.exe", path);
             return path;
         }
+        private string GetPS1FileToSign()
+        {
+            var guid = Guid.NewGuid();
+            var path = Path.Combine(_scratchDirectory.FullName, $"{guid}.ps1");
+            File.WriteAllText(path, "Write-Host \"Hello, World!\"");
+            return path;
+        }
 
         public void Dispose()
         {