diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 94de72a2..dbc5855e 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -59,7 +59,7 @@ jobs:
         COLOR: 'yes'
       run: |
         pip uninstall --yes httpx
-        HTTP_BACKEND='aiohttp' make mototest
+        HTTP_BACKEND='aiohttp' FLAGS='--cov-append' make mototest
     - name: Upload coverage to Codecov
       if: matrix.python-version == '3.11'
       uses: codecov/codecov-action@v3.1.5
diff --git a/Makefile b/Makefile
index f1f5889c..e994da18 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 # Some simple testing tasks (sorry, UNIX only).
 
-FLAGS=
+FLAGS?=
 # ?= is assignment conditional on it not being set
 HTTP_BACKEND?='all'
 
@@ -24,7 +24,7 @@ cov cover coverage: pre-commit
 mototest:
 	docker pull alpine
 	docker pull lambci/lambda:python3.8
-	BOTO_CONFIG=/dev/null python -Wd -X tracemalloc=5 -X faulthandler -m pytest -vv -m moto -n auto --cov-report term --cov-report html --cov-report xml --cov=aiobotocore --cov=tests --log-cli-level=DEBUG --http-backend=$(HTTP_BACKEND) aiobotocore tests
+	BOTO_CONFIG=/dev/null python -Wd -X tracemalloc=5 -X faulthandler -m pytest -vv -m moto -n auto --cov-report term --cov-report html --cov-report xml --cov=aiobotocore --cov=tests --log-cli-level=DEBUG --http-backend=$(HTTP_BACKEND) $(FLAGS) aiobotocore tests
 	@echo "open file://`pwd`/htmlcov/index.html"
 
 clean: