diff --git a/tests/lib/prepare.sh b/tests/lib/prepare.sh
index 5576eb314f7..4a8459a4961 100755
--- a/tests/lib/prepare.sh
+++ b/tests/lib/prepare.sh
@@ -410,7 +410,7 @@ EOF
     fi
 
     # extra_snap should contain only ONE snap
-    if "${#extra_snap[@]}" -ne 1; then
+    if [ "${#extra_snap[@]}" -ne 1 ]; then
         echo "unexpected number of globbed snaps: ${extra_snap[*]}"
         exit 1
     fi