diff --git a/tests/btrfs/139 b/tests/btrfs/139
index 5664617c..1b636e81 100755
--- a/tests/btrfs/139
+++ b/tests/btrfs/139
@@ -33,7 +33,8 @@ rm -f $seqres.full
 
 _supported_fs btrfs
 _supported_os Linux
-_require_scratch
+# We at least need 2GB of free space on $SCRATCH_DEV
+_require_scratch_size $((2 * 1024 * 1024))
 
 _scratch_mkfs > /dev/null 2>&1
 _scratch_mount