diff --git a/S7.Net/PLCExceptions.cs b/S7.Net/PLCExceptions.cs
index 2b1034d4..1bbc9a63 100644
--- a/S7.Net/PLCExceptions.cs
+++ b/S7.Net/PLCExceptions.cs
@@ -6,7 +6,7 @@
 
 namespace S7.Net
 {
-    internal class WrongNumberOfBytesException : Exception
+    public class WrongNumberOfBytesException : Exception
     {
         public WrongNumberOfBytesException() : base()
         {
@@ -27,7 +27,7 @@ protected WrongNumberOfBytesException(SerializationInfo info, StreamingContext c
         #endif
     }
 
-    internal class InvalidAddressException : Exception
+    public class InvalidAddressException : Exception
     {
         public InvalidAddressException() : base ()
         {
@@ -48,7 +48,7 @@ protected InvalidAddressException(SerializationInfo info, StreamingContext conte
         #endif
     }
 
-    internal class InvalidVariableTypeException : Exception
+    public class InvalidVariableTypeException : Exception
     {
         public InvalidVariableTypeException() : base()
         {
@@ -69,7 +69,7 @@ protected InvalidVariableTypeException(SerializationInfo info, StreamingContext
         #endif
     }
 
-    internal class TPKTInvalidException : Exception
+    public class TPKTInvalidException : Exception
     {
         public TPKTInvalidException() : base()
         {
@@ -90,7 +90,7 @@ protected TPKTInvalidException(SerializationInfo info, StreamingContext context)
         #endif
     }
 
-    internal class TPDUInvalidException : Exception
+    public class TPDUInvalidException : Exception
     {
         public TPDUInvalidException() : base()
         {