diff --git a/devtools/test-null.sh b/devtools/test-null.sh
index 4ba57a6829..6cd34f64f1 100755
--- a/devtools/test-null.sh
+++ b/devtools/test-null.sh
@@ -27,6 +27,7 @@ else
 fi
 
 (sleep 1 && echo stop) |
-$testpmd -c $coremask --no-huge -m 20 \
+# testpmd only needs 20M, make it x2 (default number of cores) for NUMA systems
+$testpmd -c $coremask --no-huge -m 40 \
 	$libs -a 0:0.0 --vdev net_null1 --vdev net_null2 $eal_options -- \
 	--no-mlockall --total-num-mbufs=2048 $testpmd_options -ia