diff --git a/packages/core/.c8rc.json b/packages/core/.c8rc.json
index 2d34c12a557..ddda08a8dce 100644
--- a/packages/core/.c8rc.json
+++ b/packages/core/.c8rc.json
@@ -1,7 +1,6 @@
 {
-  "reporter": "html",
+  "reporter": "lcov",
   "all": true,
   "extension": "mjs",
   "exclude": ["node_modules/*", "tests"]
 }
-
diff --git a/packages/core/package.json b/packages/core/package.json
index 5cc0bcd8139..738e3cea774 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -41,7 +41,7 @@
     "tips": "node ../../scripts/help.mjs",
     "lint": "npx eslint 'src/*.mjs' 'tests/*.mjs'",
     "report": "c8 report",
-    "testci": "mocha tests/*.test.mjs",
+    "testci": "c8 mocha tests/*.test.mjs",
     "prettier": "npx prettier --write 'src/*.mjs' 'tests/*.mjs'",
     "jsdoc": "jsdoc -c jsdoc.json -r src",
     "cibuild_step0": "node build.mjs",