diff --git a/SimpleMsgPack.pas b/SimpleMsgPack.pas
index b4d90c8..1836d80 100644
--- a/SimpleMsgPack.pas
+++ b/SimpleMsgPack.pas
@@ -1958,6 +1958,7 @@ procedure TSimpleMsgPack.SetAsVariant(const Value: Variant);
       for I := VarArrayLowBound(Value, VarArrayDimCount(Value))
         to VarArrayHighBound(Value, VarArrayDimCount(Value)) do
         Add.AsVariant := Value[I];
+      FDataType := mptArray;
     end;
   end
   else