diff --git a/csharp/src/Google.Protobuf/WritingPrimitives.cs b/csharp/src/Google.Protobuf/WritingPrimitives.cs
index 030f06c7e1a9..8ad483042260 100644
--- a/csharp/src/Google.Protobuf/WritingPrimitives.cs
+++ b/csharp/src/Google.Protobuf/WritingPrimitives.cs
@@ -164,7 +164,6 @@ public static void WriteBool(ref Span<byte> buffer, ref WriterInternalState stat
         /// </summary>
         public static void WriteString(ref Span<byte> buffer, ref WriterInternalState state, string value)
         {
-#if !NETSTANDARD1_1
             const int MaxBytesPerChar = 3;
             const int MaxSmallStringLength = 128 / MaxBytesPerChar;
 
@@ -174,10 +173,11 @@ public static void WriteString(ref Span<byte> buffer, ref WriterInternalState st
             // This saves calling GetByteCount on the string. We get the string length from GetBytes.
             if (value.Length <= MaxSmallStringLength && buffer.Length - state.position - 1 >= value.Length * MaxBytesPerChar)
             {
+                // Get the original position, then increment it on state by 1, then write string to buffer.
+                // Method will return byte length, which is then set to the original position.
                 buffer[state.position++] = (byte)WriteStringToBuffer(buffer, ref state, value);
                 return;
             }
-#endif
 
             int length = Utf8Encoding.GetByteCount(value);
             WriteLength(ref buffer, ref state, length);