diff --git a/lib/run-status.js b/lib/run-status.js
index 6526f7bdc..609c79a87 100644
--- a/lib/run-status.js
+++ b/lib/run-status.js
@@ -73,6 +73,7 @@ class RunStatus extends EventEmitter {
 	}
 	handleTeardown(data) {
 		this.emit('dependencies', data.file, data.dependencies, this);
+		this.emit('touchedFiles', data.touchedFiles);
 	}
 	handleStats(stats) {
 		this.emit('stats', stats, this);
diff --git a/lib/runner.js b/lib/runner.js
index d2533c3a2..7a561c298 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -195,7 +195,10 @@ class Runner extends EventEmitter {
 
 	saveSnapshotState() {
 		if (this.snapshots) {
-			this.snapshots.save();
+			const files = this.snapshots.save();
+			if (files) {
+				this.emit('touched', files);
+			}
 		} else if (this.updateSnapshots) {
 			// TODO: There may be unused snapshot files if no test caused the
 			// snapshots to be loaded. Prune them. But not if tests (including hooks!)
diff --git a/lib/snapshot-manager.js b/lib/snapshot-manager.js
index 8396d21b7..e2cd3a25d 100644
--- a/lib/snapshot-manager.js
+++ b/lib/snapshot-manager.js
@@ -5,11 +5,11 @@ const fs = require('fs');
 const path = require('path');
 const zlib = require('zlib');
 
+const writeFileAtomic = require('@ava/write-file-atomic');
 const concordance = require('concordance');
 const indentString = require('indent-string');
 const makeDir = require('make-dir');
 const md5Hex = require('md5-hex');
-const writeFileAtomic = require('write-file-atomic');
 
 const concordanceOptions = require('./concordance-options').snapshotManager;
 
@@ -333,7 +333,7 @@ class Manager {
 
 	save() {
 		if (!this.hasChanges) {
-			return;
+			return null;
 		}
 
 		const snapPath = path.join(this.dir, this.snapFile);
@@ -346,8 +346,10 @@ class Manager {
 			generateReport(this.relFile, this.snapFile, this.reportEntries);
 
 		makeDir.sync(this.dir);
-		writeFileAtomic.sync(snapPath, buffer);
-		writeFileAtomic.sync(reportPath, reportBuffer);
+		const tmpSnapPath = writeFileAtomic.sync(snapPath, buffer);
+		const tmpReportPath = writeFileAtomic.sync(reportPath, reportBuffer);
+
+		return [tmpSnapPath, tmpReportPath, snapPath, reportPath];
 	}
 }
 
diff --git a/lib/test-worker.js b/lib/test-worker.js
index aa1ca998c..10faa10c0 100644
--- a/lib/test-worker.js
+++ b/lib/test-worker.js
@@ -42,10 +42,17 @@ const testPath = opts.file;
 const dependencies = [];
 adapter.installDependencyTracking(dependencies, testPath);
 
+const touchedFiles = new Set();
+
 // Set when main.js is required (since test files should have `require('ava')`).
 let runner = null;
 exports.setRunner = newRunner => {
 	runner = newRunner;
+	runner.on('touched', files => {
+		for (const file of files) {
+			touchedFiles.add(file);
+		}
+	});
 };
 
 require(testPath);
@@ -123,8 +130,9 @@ process.on('ava-teardown', () => {
 
 	// Include dependencies in the final teardown message. This ensures the full
 	// set of dependencies is included no matter how the process exits, unless
-	// it flat out crashes.
-	adapter.send('teardown', {dependencies});
+	// it flat out crashes. Also include any files that AVA touched during the
+	// test run. This allows the watcher to ignore modifications to those files.
+	adapter.send('teardown', {dependencies, touchedFiles: Array.from(touchedFiles)});
 });
 
 process.on('ava-exit', () => {
diff --git a/lib/watcher.js b/lib/watcher.js
index 66dc9f1e5..d07a155a8 100644
--- a/lib/watcher.js
+++ b/lib/watcher.js
@@ -116,6 +116,7 @@ class Watcher {
 				}
 			}
 
+			this.touchedFiles.clear();
 			this.busy = api.run(specificFiles || files, {runOnlyExclusive})
 				.then(runStatus => {
 					runStatus.previousFailCount = this.sumPreviousFailures(currentVector);
@@ -130,6 +131,9 @@ class Watcher {
 		this.testDependencies = [];
 		this.trackTestDependencies(api, sources);
 
+		this.touchedFiles = new Set();
+		this.trackTouchedFiles(api);
+
 		this.filesWithExclusiveTests = [];
 		this.trackExclusivity(api);
 
@@ -184,6 +188,15 @@ class Watcher {
 			this.testDependencies.push(new TestDependency(file, sources));
 		}
 	}
+	trackTouchedFiles(api) {
+		api.on('test-run', runStatus => {
+			runStatus.on('touchedFiles', files => {
+				for (const file of files) {
+					this.touchedFiles.add(nodePath.relative(process.cwd(), file));
+				}
+			});
+		});
+	}
 	trackExclusivity(api) {
 		api.on('stats', stats => {
 			this.updateExclusivity(stats.file, stats.hasExclusive);
@@ -284,7 +297,14 @@ class Watcher {
 		const dirtyStates = this.dirtyStates;
 		this.dirtyStates = {};
 
-		const dirtyPaths = Object.keys(dirtyStates);
+		const dirtyPaths = Object.keys(dirtyStates).filter(path => {
+			if (this.touchedFiles.has(path)) {
+				debug('Ignoring known touched file %s', path);
+				this.touchedFiles.delete(path);
+				return false;
+			}
+			return true;
+		});
 		const dirtyTests = dirtyPaths.filter(this.avaFiles.isTest);
 		const dirtySources = diff(dirtyPaths, dirtyTests);
 		const addedOrChangedTests = dirtyTests.filter(path => dirtyStates[path] !== 'unlink');
diff --git a/package-lock.json b/package-lock.json
index a024f06b8..60f4874a4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -30,6 +30,11 @@
       "resolved": "https://registry.npmjs.org/@ava/babel-preset-transform-test-files/-/babel-preset-transform-test-files-3.0.0.tgz",
       "integrity": "sha1-ze0RlqjY2TgaUJJAq5LpGl7Aafc="
     },
+    "@ava/write-file-atomic": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@ava/write-file-atomic/-/write-file-atomic-2.2.0.tgz",
+      "integrity": "sha512-BTNB3nGbEfJT+69wuqXFr/bQH7Vr7ihx2xGOMNqPgDGhwspoZhiWumDDZNjBy7AScmqS5CELIOGtPVXESyrnDA=="
+    },
     "@concordance/react": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/@concordance/react/-/react-0.2.0.tgz",
diff --git a/package.json b/package.json
index d198603d1..43ec27d81 100644
--- a/package.json
+++ b/package.json
@@ -95,6 +95,7 @@
   "dependencies": {
     "@ava/babel-preset-stage-4": "^1.1.0",
     "@ava/babel-preset-transform-test-files": "^3.0.0",
+    "@ava/write-file-atomic": "^2.2.0",
     "@concordance/react": "^0.2.0",
     "ansi-escapes": "^2.0.0",
     "ansi-styles": "^3.1.0",
@@ -170,8 +171,7 @@
     "time-require": "^0.1.2",
     "trim-off-newlines": "^1.0.1",
     "unique-temp-dir": "^1.0.0",
-    "update-notifier": "^2.1.0",
-    "write-file-atomic": "^1.3.4"
+    "update-notifier": "^2.1.0"
   },
   "devDependencies": {
     "cli-table2": "^0.2.0",
diff --git a/test/cli.js b/test/cli.js
index 5a92ec3c7..6e008da9a 100644
--- a/test/cli.js
+++ b/test/cli.js
@@ -307,6 +307,32 @@ test('watcher reruns test files when source dependencies change', t => {
 	});
 });
 
+test('watcher does not rerun test files when they write snapshot files', t => {
+	let killed = false;
+
+	const child = execCli(['--verbose', '--watch', '--update-snapshots', 'test.js'], {dirname: 'fixture/snapshots'}, err => {
+		t.ok(killed);
+		t.ifError(err);
+		t.end();
+	});
+
+	let buffer = '';
+	let passedFirst = false;
+	child.stderr.on('data', str => {
+		buffer += str;
+		if (/2 tests passed/.test(buffer) && !passedFirst) {
+			buffer = '';
+			passedFirst = true;
+			setTimeout(() => {
+				child.kill();
+				killed = true;
+			}, 500);
+		} else if (passedFirst && !killed) {
+			t.is(buffer.replace(/\s/g, ''), '');
+		}
+	});
+});
+
 test('`"tap": true` config is ignored when --watch is given', t => {
 	let killed = false;
 
diff --git a/test/fixture/snapshots/package.json b/test/fixture/snapshots/package.json
new file mode 100644
index 000000000..2213e8988
--- /dev/null
+++ b/test/fixture/snapshots/package.json
@@ -0,0 +1,5 @@
+{
+	"ava": {
+		"source": "**/*"
+	}
+}