diff --git a/README.md b/README.md
index c9b8d23..edccfda 100644
--- a/README.md
+++ b/README.md
@@ -109,5 +109,21 @@ POSITIONAL ARGUMENTS:
 test: Runs mocha tests
 
 For global options help run: hardhat help
-```
+````
+### Changed file as argument
+
+The path of the changed file can be inserted into positional arguments using the template parameter `{path}`. This speeds up iteration in testing, especially if using single test isolation (for example, by using `it.only("test")` in mocha.)
+
+Example:
+````
+module.exports = {
+  watcher: {
+    test: {
+      tasks: [{ command: 'test', params: { testFiles: ['{path}'] } }],
+      files: ['./test/**/*'],
+      verbose: true
+    }
+  }
+}
+````
 
diff --git a/package.json b/package.json
index c0f2475..17873e6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hardhat-watcher",
-  "version": "2.0.0",
+  "version": "2.1.1",
   "description": "Hardhat file watcher plugin",
   "repository": "https://github.com/N1ghtly/hardhat-watcher",
   "author": "Xander Deseyn",
diff --git a/src/index.ts b/src/index.ts
index 1f695f7..ef3d77b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -56,6 +56,24 @@ task("watch", "Start the file watcher")
 
       logVerbose("Starting file watcher", taskConfig.files);
 
+      const templateReplace = (value: any, pattern: string, replace: string) => {
+        if (Array.isArray(value)) {
+          return value.map(v => v.replace(pattern, replace));
+        } else if (typeof(value) == 'string') {
+          return value.replace(pattern, replace);
+        } else {
+          return value
+        }
+      }
+
+      const paramsTemplateReplace = (params: any, pattern: string, replace: string) => {
+        const newParams: any = {}
+        Object.keys(params).forEach(k => {
+          newParams[k] = templateReplace(params[k], pattern, replace)
+        });
+        return newParams;
+      }
+
       // Validate tasks
       taskConfig.tasks.forEach((task) => {
         if (!(task.command in tasks)) {
@@ -73,16 +91,20 @@ task("watch", "Start the file watcher")
           usePolling: true,
           interval: 250,
         })
-        .on("change", async () => {
+        .on("change", async path => {
           for (let i = 0; i < taskConfig.tasks.length; i++) {
             const task = taskConfig.tasks[i];
+
+            // Replace template pattern with the changed file
+            const newParams = paramsTemplateReplace(task.params, '{path}', path)
+
             logVerbose(
               `Running task "${task.command}" with params ${JSON.stringify(
-                task.params
+                newParams
               )}`
             );
             try {
-              await run(task.command, task.params);
+              await run(task.command, newParams);
               // This hack is required to allow running Mocha commands. Check out https://github.com/mochajs/mocha/issues/1938 for more details.
               Object.keys(require.cache).forEach(function (key) {
                 if (key.startsWith(paths.tests)) {