diff --git a/src/iTextSharp.LGPLv2.Core/System/util/zlib/ZDeflaterOutputStream.cs b/src/iTextSharp.LGPLv2.Core/System/util/zlib/ZDeflaterOutputStream.cs
index 3922f29..7d66fdb 100644
--- a/src/iTextSharp.LGPLv2.Core/System/util/zlib/ZDeflaterOutputStream.cs
+++ b/src/iTextSharp.LGPLv2.Core/System/util/zlib/ZDeflaterOutputStream.cs
@@ -78,7 +78,11 @@ public override long Position
             }
         }
 
+#if NETSTANDARD1_3
         public void Close()
+#else
+        public override void Close()
+#endif
         {
             try
             {
diff --git a/src/iTextSharp.LGPLv2.Core/iTextSharp.LGPLv2.Core.csproj b/src/iTextSharp.LGPLv2.Core/iTextSharp.LGPLv2.Core.csproj
index 65681e6..2b596f2 100644
--- a/src/iTextSharp.LGPLv2.Core/iTextSharp.LGPLv2.Core.csproj
+++ b/src/iTextSharp.LGPLv2.Core/iTextSharp.LGPLv2.Core.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Description> iTextSharp.LGPLv2.Core is an unofficial port of the last LGPL version of the iTextSharp (V4.1.6) to .NET Core.</Description>
-    <VersionPrefix>1.3.2</VersionPrefix>
+    <VersionPrefix>1.3.3</VersionPrefix>
     <LangVersion>latest</LangVersion>
     <Authors>Vahid Nasiri</Authors>
     <TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>
diff --git a/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/AcroFields.cs b/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/AcroFields.cs
index b5a41ea..6d8d169 100644
--- a/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/AcroFields.cs
+++ b/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/AcroFields.cs
@@ -2634,7 +2634,11 @@ public override long Position
                 }
             }
 
+#if NETSTANDARD1_3
             public void Close()
+#else
+            public override void Close()
+#endif
             {
                 if (!_closed)
                 {
diff --git a/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/OutputStreamEncryption.cs b/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/OutputStreamEncryption.cs
index bf6e65c..b5e4ce9 100644
--- a/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/OutputStreamEncryption.cs
+++ b/src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/OutputStreamEncryption.cs
@@ -81,7 +81,11 @@ public override long Position
             }
         }
 
+#if NETSTANDARD1_3
         public void Close()
+#else
+        public override void Close()
+#endif
         {
             Finish();
         }