diff --git a/reactos/lib/user32/misc/display.c b/reactos/lib/user32/misc/display.c
index 00d26bf903c..f1670af8c3f 100644
--- a/reactos/lib/user32/misc/display.c
+++ b/reactos/lib/user32/misc/display.c
@@ -61,7 +61,7 @@ EnumDisplayDevicesA(
       return FALSE;
     }
 
-  DisplayDeviceW.cb = lpDisplayDevice->cb;
+  DisplayDeviceW.cb = sizeof(DISPLAY_DEVICEW);  
   rc = NtUserEnumDisplayDevices (
     &Device,
     iDevNum,