diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
new file mode 100644
index 0000000..4cc6928
--- /dev/null
+++ b/.config/dotnet-tools.json
@@ -0,0 +1,13 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "dotnet-stryker": {
+      "version": "4.15.0",
+      "commands": [
+        "dotnet-stryker"
+      ],
+      "rollForward": false
+    }
+  }
+}
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 91aea34..1053420 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,6 +15,9 @@ coverage*.json
 coverage*.xml
 *.coverage
 
+# Stryker.NET mutation-testing reports (regenerated by `make mutation`)
+StrykerOutput/
+
 # Rider / VS / VS Code
 .idea/
 .vs/