diff --git a/meta-raspberrypi/recipes-sato/libwpe_%.bbappend b/meta-raspberrypi/recipes-sato/libwpe_%.bbappend
new file mode 100644
index 0000000..fe1e59b
--- /dev/null
+++ b/meta-raspberrypi/recipes-sato/libwpe_%.bbappend
@@ -0,0 +1,2 @@
+# Workaround build issue with RPi userland EGL libraries.
+CFLAGS:append:rpi = " ${@bb.utils.contains('MACHINE_FEATURES', 'vc4graphics', '', '-D_GNU_SOURCE', d)}"