diff --git a/sip/tdefx/tdestyle.sip b/sip/tdefx/tdestyle.sip
index 2d5f043..b2c04f2 100644
--- a/sip/tdefx/tdestyle.sip
+++ b/sip/tdefx/tdestyle.sip
@@ -27,6 +27,7 @@
 class TDEStyle : TQCommonStyle
 {
 %TypeHeaderCode
+#define ENABLE_TQSTYLECONTROLELEMENTDATA_SLOW_COPY 1
 #include <tdestyle.h>
 %End