diff --git a/tools/ci/amd64/gcc/valgrind.supp b/tools/ci/amd64/gcc/valgrind.supp
index 0203858..673fd2d 100644
--- a/tools/ci/amd64/gcc/valgrind.supp
+++ b/tools/ci/amd64/gcc/valgrind.supp
@@ -1,3 +1,8 @@
+{
+   xflush
+   Memcheck:Param
+   src:xcb_io.c:604
+}
 {
    <insert_a_suppression_name_here>
    Memcheck:Param