diff --git a/test/cases/040_packages/005_extend/000_ext4/check.sh b/test/cases/040_packages/005_extend/000_ext4/check.sh
index c14eef3c5..04b9466da 100755
--- a/test/cases/040_packages/005_extend/000_ext4/check.sh
+++ b/test/cases/040_packages/005_extend/000_ext4/check.sh
@@ -9,5 +9,5 @@ function failed {
 
 [ -f /var/lib/docker/bar ] || failed
 touch /var/lib/docker/foo || failed
-df -h | grep -q "490.9M" || failed
+df -h | grep -qE "[4-5][0-9]{2}\.[0-9]{1,}M" || failed
 printf "extend test suite PASSED\n" >&1
diff --git a/test/cases/040_packages/005_extend/001_btrfs/check.sh b/test/cases/040_packages/005_extend/001_btrfs/check.sh
index 905634e7d..04b9466da 100755
--- a/test/cases/040_packages/005_extend/001_btrfs/check.sh
+++ b/test/cases/040_packages/005_extend/001_btrfs/check.sh
@@ -9,5 +9,5 @@ function failed {
 
 [ -f /var/lib/docker/bar ] || failed
 touch /var/lib/docker/foo || failed
-df -h | grep -q "511.0M" || failed
+df -h | grep -qE "[4-5][0-9]{2}\.[0-9]{1,}M" || failed
 printf "extend test suite PASSED\n" >&1
diff --git a/test/cases/040_packages/005_extend/002_xfs/check.sh b/test/cases/040_packages/005_extend/002_xfs/check.sh
index 943fabc04..04b9466da 100755
--- a/test/cases/040_packages/005_extend/002_xfs/check.sh
+++ b/test/cases/040_packages/005_extend/002_xfs/check.sh
@@ -9,5 +9,5 @@ function failed {
 
 [ -f /var/lib/docker/bar ] || failed
 touch /var/lib/docker/foo || failed
-df -h | grep -q "504.8M" || failed
+df -h | grep -qE "[4-5][0-9]{2}\.[0-9]{1,}M" || failed
 printf "extend test suite PASSED\n" >&1