diff --git a/tests/test.sh b/tests/test.sh
index 8e84e47..6a7d4d0 100755
--- a/tests/test.sh
+++ b/tests/test.sh
@@ -2,7 +2,7 @@
 set -euo pipefail
 
 IMAGE="${1:?Usage: test.sh <image>}"
-CONTAINER_NAME="test-$(basename "$IMAGE")-$$"
+CONTAINER_NAME="test-$(echo "$IMAGE" | tr ':/' '-')-$$"
 PASSED=0
 FAILED=0
 TOTAL=0