diff --git a/jobs/ttcn3-testsuites.yml b/jobs/ttcn3-testsuites.yml
index 2e01645..2c3e07d 100644
--- a/jobs/ttcn3-testsuites.yml
+++ b/jobs/ttcn3-testsuites.yml
@@ -301,8 +301,8 @@
                   ;;
               *-io_uring)
                   DIR="$(echo "{job-name}" | sed s/\-io_uring$//)"
-                  # OS#6405: set memlock to 1 GB for older kernels
-                  export DOCKER_ARGS="-e LIBOSMO_IO_BACKEND=IO_URING --ulimit memlock=1000000"
+                  # OS#6405: set memlock to unlimited for older kernels
+                  export DOCKER_ARGS="-e LIBOSMO_IO_BACKEND=IO_URING --ulimit memlock=-1"
                   ;;
               *-latest)
                   DIR="$(echo "{job-name}" | sed s/\-latest$//)"