diff --git a/tests/qemu-iotests/159 b/tests/qemu-iotests/159
index 825f05f..9b0e1ec 100755
--- a/tests/qemu-iotests/159
+++ b/tests/qemu-iotests/159
@@ -40,6 +40,7 @@
 _supported_fmt generic
 _supported_proto file
 _supported_os Linux
+_unsupported_fmt luks
 
 TEST_SIZES="5 512 1024 1999 1K 64K 1M"
 
diff --git a/tests/qemu-iotests/170 b/tests/qemu-iotests/170
index 5b335db..b79359f 100755
--- a/tests/qemu-iotests/170
+++ b/tests/qemu-iotests/170
@@ -40,6 +40,7 @@
 _supported_fmt generic
 _supported_proto file
 _supported_os Linux
+_unsupported_fmt luks
 
 echo
 echo "== Creating image =="