diff --git a/include/X11/Xlibint.h b/include/X11/Xlibint.h
index 50099b4..4b388f4 100644
--- a/include/X11/Xlibint.h
+++ b/include/X11/Xlibint.h
@@ -45,6 +45,7 @@ from The Open Group.
 
 #ifdef XTHREADS
 #include <X11/Xthreads.h>
+#undef CreateWindow /* conda-forge: work around bug in Xwindows.h exposed here */
 #endif
 
 /* The Xlib structs are full of implicit padding to properly align members.