diff --git a/PiwigoDotnet/Piwigo.Client/CapturedMultipartContentExtensions.cs b/PiwigoDotnet/Piwigo.Client/CapturedMultipartContentExtensions.cs
deleted file mode 100644
index fb56758..0000000
--- a/PiwigoDotnet/Piwigo.Client/CapturedMultipartContentExtensions.cs
+++ /dev/null
@@ -1,16 +0,0 @@
-using Flurl.Http.Content;
-
-namespace Piwigo.Client;
-
-internal static class CapturedMultipartContentExtensions
-{
-    public static CapturedMultipartContent AddMethod(this CapturedMultipartContent part, string piwigoMethod)
-    {
-        if (string.IsNullOrWhiteSpace(piwigoMethod))
-        {
-            throw new ArgumentException("Value cannot be null or whitespace.", nameof(piwigoMethod));
-        }
-
-        return part.AddString("method", piwigoMethod);
-    }
-}
\ No newline at end of file
diff --git a/PiwigoDotnet/Piwigo.Client/PiwigoMethods.cs b/PiwigoDotnet/Piwigo.Client/PiwigoMethods.cs
index 0ec2717..49b9b31 100644
--- a/PiwigoDotnet/Piwigo.Client/PiwigoMethods.cs
+++ b/PiwigoDotnet/Piwigo.Client/PiwigoMethods.cs
@@ -19,4 +19,14 @@ internal static class PiwigoMethods
     {
         return part.AddMethod("pwg.session.getStatus");
     }
+
+    private static CapturedMultipartContent AddMethod(this CapturedMultipartContent part, string piwigoMethod)
+    {
+        if (string.IsNullOrWhiteSpace(piwigoMethod))
+        {
+            throw new ArgumentException("Value cannot be null or whitespace.", nameof(piwigoMethod));
+        }
+
+        return part.AddString("method", piwigoMethod);
+    }
 }
\ No newline at end of file