diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 240ed0697a..4befd865f4 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -35,7 +35,7 @@ _filter_generated_node_ids()
 # replace occurrences of the actual TEST_DIR value with TEST_DIR
 _filter_testdir()
 {
-    sed -e "s#$TEST_DIR#TEST_DIR#g"
+    sed -e "s#$TEST_DIR/#TEST_DIR/#g"
 }
 
 # replace occurrences of the actual IMGFMT value with IMGFMT