diff --git a/packages/libx11/configure.patch b/packages/libx11/configure.patch
new file mode 100644
index 000000000..4ddfec979
--- /dev/null
+++ b/packages/libx11/configure.patch
@@ -0,0 +1,20 @@
+diff -uNr libX11-1.7.0/configure libX11-1.7.0.mod/configure
+--- libX11-1.7.0/configure	2020-11-20 19:08:19.000000000 +0000
++++ libX11-1.7.0.mod/configure	2020-12-07 23:41:45.588377415 +0000
+@@ -19609,6 +19609,7 @@
+ # Check for flag to avoid builtin definitions - assumes unix is predefined,
+ # which is not the best choice for supporting other OS'es, but covers most
+ # of the ones we need for now.
++if false; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking if $RAWCPP requires -undef" >&5
+ $as_echo_n "checking if $RAWCPP requires -undef... " >&6; }
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+@@ -19654,7 +19655,7 @@
+ 	fi
+ fi
+ rm -f conftest.$ac_ext
+-
++fi
+ 
+ 
+