diff --git a/tests/qemu-iotests/031 b/tests/qemu-iotests/031
index 2d5e3b1..c9070b0 100755
--- a/tests/qemu-iotests/031
+++ b/tests/qemu-iotests/031
@@ -56,22 +56,22 @@
     echo === Create image with unknown header extension ===
     echo
     _make_test_img 64M
-    ./qcow2.py $TEST_IMG add-header-ext 0x12345678 "This is a test header extension"
-    ./qcow2.py $TEST_IMG dump-header
+    ./qcow2.py "$TEST_IMG" add-header-ext 0x12345678 "This is a test header extension"
+    ./qcow2.py "$TEST_IMG" dump-header
     _check_test_img
 
     echo
     echo === Rewrite header with no backing file ===
     echo
-    $QEMU_IMG rebase -u -b "" $TEST_IMG
-    ./qcow2.py $TEST_IMG dump-header
+    $QEMU_IMG rebase -u -b "" "$TEST_IMG"
+    ./qcow2.py "$TEST_IMG" dump-header
     _check_test_img
 
     echo
     echo === Add a backing file and format ===
     echo
-    $QEMU_IMG rebase -u -b "/some/backing/file/path" -F host_device $TEST_IMG
-    ./qcow2.py $TEST_IMG dump-header
+    $QEMU_IMG rebase -u -b "/some/backing/file/path" -F host_device "$TEST_IMG"
+    ./qcow2.py "$TEST_IMG" dump-header
 done
 
 # success, all done