diff --git a/src/UglyToad.PdfPig.Tests/Encryption/AesEncryptionHelperTests.cs b/src/UglyToad.PdfPig.Tests/Encryption/AesEncryptionHelperTests.cs
index 6a07a911..1ae27525 100644
--- a/src/UglyToad.PdfPig.Tests/Encryption/AesEncryptionHelperTests.cs
+++ b/src/UglyToad.PdfPig.Tests/Encryption/AesEncryptionHelperTests.cs
@@ -23,7 +23,9 @@ namespace UglyToad.PdfPig.Tests.Encryption
 
             var output = AesEncryptionHelper.Decrypt(data, key);
 
-            Assert.Equal("D:20180808103317-07'00'", OtherEncodings.BytesAsLatin1String(output));
+            var actual = OtherEncodings.BytesAsLatin1String(output);
+
+            Assert.Equal("D:20180808103317-07'00'", actual);
         }
     }
 }
diff --git a/src/UglyToad.PdfPig/Encryption/AesEncryptionHelper.cs b/src/UglyToad.PdfPig/Encryption/AesEncryptionHelper.cs
index 3e4cd7b6..7f4a246d 100644
--- a/src/UglyToad.PdfPig/Encryption/AesEncryptionHelper.cs
+++ b/src/UglyToad.PdfPig/Encryption/AesEncryptionHelper.cs
@@ -35,16 +35,16 @@
                     input.Seek(iv.Length, SeekOrigin.Begin);
                     using (var cryptoStream = new CryptoStream(input, decryptor, CryptoStreamMode.Read))
                     {
+                        var offset = 0;
                         int read;
-                        while ((read = cryptoStream.Read(buffer, 0, buffer.Length)) != -1)
+                        do
                         {
-                            output.Write(buffer, 0, read);
+                            read = cryptoStream.Read(buffer, offset, buffer.Length - offset);
 
-                            if (read < buffer.Length)
-                            {
-                                break;
-                            }
-                        }
+                            output.Write(buffer, offset, read);
+
+                            offset += read;
+                        } while (read > 0);
 
                         return output.ToArray();
                     }