diff --git a/.github/workflows/ci-test.yml b/.github/workflows/ci-test.yml
index 510479aa..f601e44d 100644
--- a/.github/workflows/ci-test.yml
+++ b/.github/workflows/ci-test.yml
@@ -90,7 +90,6 @@ jobs:
       #CACHIER_TEST_DB: "dummy_db"
       #CACHIER_TEST_USERNAME: "myuser"
       #CACHIER_TEST_PASSWORD: "yourpassword"
-      CACHIER_TEST_VS_DOCKERIZED_MONGO: "true"
       CACHIER_TEST_REDIS_HOST: "localhost"
       CACHIER_TEST_REDIS_PORT: "6379"
       CACHIER_TEST_REDIS_DB: "0"
@@ -137,7 +136,7 @@ jobs:
       #    prefix-key: "mongo-db"
       #    images: mongo:8
       - name: Start MongoDB in docker
-        if: matrix.backend == 'mongodb'
+        if: matrix.backend == 'mongodb' && runner.os != 'Windows'
         run: |
           # start MongoDB in a container
           docker run -d -p ${{ env.CACHIER_TEST_PORT }}:27017 --name mongodb mongo:8
@@ -146,9 +145,18 @@ jobs:
           # show running containers
           docker ps -a
 
-      - name: Unit tests (DB)
-        if: matrix.backend == 'mongodb'
+      - name: Unit tests (MongoDB, Docker)
+        if: matrix.backend == 'mongodb' && runner.os != 'Windows'
+        env:
+          CACHIER_TEST_VS_DOCKERIZED_MONGO: "true"
         run: pytest -m "mongo" --cov=cachier --cov-report=term --cov-report=xml:cov.xml
+
+      - name: Unit tests (MongoDB, in-memory)
+        if: matrix.backend == 'mongodb' && runner.os == 'Windows'
+        env:
+          CACHIER_TEST_VS_DOCKERIZED_MONGO: "false"
+        run: pytest -m "mongo" --cov=cachier --cov-report=term --cov-report=xml:cov.xml
+
       - name: Speed eval
         run: python tests/speed_eval.py
 
diff --git a/README.rst b/README.rst
index 3d42fd9a..e9319eb9 100644
--- a/README.rst
+++ b/README.rst
@@ -853,11 +853,11 @@ This script automatically handles Docker container lifecycle, environment variab
   # Clean up
   docker stop cachier-test-mongo && docker rm cachier-test-mongo
 
-**CI Environment:** The ``CACHIER_TEST_VS_DOCKERIZED_MONGO`` environment variable is set to ``True`` in the GitHub Actions CI environment, which runs tests against a real MongoDB instance on every commit and pull request.
+**CI Environment:** GitHub Actions runs MongoDB tests against a real Dockerized MongoDB instance on Linux. Windows MongoDB jobs use the in-memory MongoDB backend because GitHub-hosted Windows runners do not provide a stable Docker daemon for Linux MongoDB containers.
 
-Contributors are encouraged to test against a real MongoDB instance before submitting PRs to ensure compatibility, though the in-memory MongoDB instance serves as a good proxy for most development.
+Contributors are encouraged to test against a real MongoDB instance before submitting PRs to ensure compatibility, though the in-memory MongoDB instance serves as a good proxy for most development and CI platform coverage.
 
-**HOWEVER, the tests run against a live MongoDB instance when you submit a PR are the determining tests for deciding whether your code functions correctly against MongoDB.**
+**HOWEVER, only the Linux MongoDB CI jobs are live-server integration tests. Windows MongoDB CI jobs still exercise the Mongo backend API surface, but they are compatibility coverage over ``pymongo_inmemory`` rather than proof of live MongoDB server behavior.**
 
 
 Testing all backends locally
diff --git a/scripts/test-local.sh b/scripts/test-local.sh
index 5682da44..519ebb75 100755
--- a/scripts/test-local.sh
+++ b/scripts/test-local.sh
@@ -312,6 +312,28 @@ check_dependencies() {
     print_message $GREEN "All required dependencies are installed!"
 }
 
+run_pytest_phase() {
+    local phase_name="$1"
+    shift
+
+    print_message $BLUE "Running $phase_name: $(printf '%q ' "$@")"
+
+    local phase_exit_code=0
+    if "$@"; then
+        phase_exit_code=0
+    else
+        phase_exit_code=$?
+    fi
+
+    if [ "$phase_exit_code" -eq 0 ]; then
+        print_message $GREEN "$phase_name passed"
+    else
+        print_message $RED "$phase_name failed with exit code $phase_exit_code"
+    fi
+
+    return "$phase_exit_code"
+}
+
 # MongoDB functions
 start_mongodb() {
     print_message $YELLOW "Starting MongoDB container..."
@@ -613,23 +635,42 @@ EOF
     PYTEST_ARGS+=(--cov=cachier --cov-report="$COVERAGE_REPORT")
     SERIAL_PYTEST_ARGS+=(--cov=cachier --cov-report="$COVERAGE_REPORT" --cov-append)
 
-    # Print and run the command
-    print_message $BLUE "Running: $(printf '%q ' "${PYTEST_ARGS[@]}")"
-    "${PYTEST_ARGS[@]}"
+    MAIN_TEST_EXIT_CODE=0
+    SERIAL_TEST_EXIT_CODE=0
+    MAIN_TEST_STATUS="skipped"
+    SERIAL_TEST_STATUS="skipped"
+
+    if run_pytest_phase "main pytest phase" "${PYTEST_ARGS[@]}"; then
+        MAIN_TEST_EXIT_CODE=0
+        MAIN_TEST_STATUS="passed"
+    else
+        MAIN_TEST_EXIT_CODE=$?
+        MAIN_TEST_STATUS="failed ($MAIN_TEST_EXIT_CODE)"
+    fi
 
     if [ "$run_serial_local_tests" = true ]; then
-        print_message $BLUE "Running serial local tests (pickle, memory) with: $(printf '%q ' "${SERIAL_PYTEST_ARGS[@]}")"
-        "${SERIAL_PYTEST_ARGS[@]}"
+        if run_pytest_phase "serial local pytest phase" "${SERIAL_PYTEST_ARGS[@]}"; then
+            SERIAL_TEST_EXIT_CODE=0
+            SERIAL_TEST_STATUS="passed"
+        else
+            SERIAL_TEST_EXIT_CODE=$?
+            SERIAL_TEST_STATUS="failed ($SERIAL_TEST_EXIT_CODE)"
+        fi
     else
         print_message $BLUE "Skipping serial local tests (pickle, memory) since not requested"
     fi
 
-    TEST_EXIT_CODE=$?
+    TEST_EXIT_CODE=0
+    if [ "$MAIN_TEST_EXIT_CODE" -ne 0 ]; then
+        TEST_EXIT_CODE=$MAIN_TEST_EXIT_CODE
+    elif [ "$SERIAL_TEST_EXIT_CODE" -ne 0 ]; then
+        TEST_EXIT_CODE=$SERIAL_TEST_EXIT_CODE
+    fi
 
     if [ $TEST_EXIT_CODE -eq 0 ]; then
         print_message $GREEN "All tests passed!"
     else
-        print_message $RED "Some tests failed. Exit code: $TEST_EXIT_CODE"
+        print_message $RED "Some tests failed. Main phase: $MAIN_TEST_STATUS, serial local phase: $SERIAL_TEST_STATUS"
     fi
 
     # Exit with test status
diff --git a/tests/mongo_tests/helpers.py b/tests/mongo_tests/helpers.py
index 6af2474d..9480b939 100644
--- a/tests/mongo_tests/helpers.py
+++ b/tests/mongo_tests/helpers.py
@@ -2,7 +2,9 @@
 
 import platform
 import sys
+import warnings
 from contextlib import suppress
+from typing import Any
 from urllib.parse import quote_plus
 
 from birch import Birch  # type: ignore[import-not-found]
@@ -41,6 +43,16 @@ class CfgKey:
 _COLLECTION_NAME = f"cachier_test_{platform.system()}_{'.'.join(map(str, sys.version_info[:3]))}"
 
 
+def _build_inmemory_mongo_client() -> Any:
+    with warnings.catch_warnings():
+        warnings.filterwarnings(
+            "ignore",
+            message="Python 3.14 will, by default, filter extracted tar archives.*",
+            category=DeprecationWarning,
+        )
+        return InMemoryMongoClient()
+
+
 def _get_cachier_db_mongo_client():
     host = quote_plus(CFG[CfgKey.HOST])
     port = quote_plus(CFG[CfgKey.PORT])
@@ -55,7 +67,7 @@ def _test_mongetter():
             _test_mongetter.client = _get_cachier_db_mongo_client()
         else:
             print("Using in-memory MongoDB instance for testing.")
-            _test_mongetter.client = InMemoryMongoClient()
+            _test_mongetter.client = _build_inmemory_mongo_client()
     db_obj = _test_mongetter.client["cachier_test"]
     if _COLLECTION_NAME not in db_obj.list_collection_names():
         db_obj.create_collection(_COLLECTION_NAME)