diff --git a/packages/core/core/src/PackagerRunner.js b/packages/core/core/src/PackagerRunner.js
index 718434d6af6..f74e97df57d 100644
--- a/packages/core/core/src/PackagerRunner.js
+++ b/packages/core/core/src/PackagerRunner.js
@@ -526,10 +526,15 @@ function writeFileStream(
       ? stream.pipe(replaceStream(hashRefToNameHash))
       : stream;
     let fsStream = fs.createWriteStream(filePath, options);
+    let fsStreamClosed = new Promise(resolve => {
+      fsStream.on('close', () => resolve());
+    });
     initialStream
       .pipe(fsStream)
-      // $FlowFixMe
-      .on('finish', () => resolve(fsStream.bytesWritten))
+      .on('finish', () =>
+        // $FlowFixMe
+        resolve(fsStreamClosed.then(() => fsStream.bytesWritten)),
+      )
       .on('error', reject);
   });
 }
diff --git a/packages/core/fs/src/MemoryFS.js b/packages/core/fs/src/MemoryFS.js
index dea0ffce822..8a24c0ab732 100644
--- a/packages/core/fs/src/MemoryFS.js
+++ b/packages/core/fs/src/MemoryFS.js
@@ -642,8 +642,9 @@ class WriteStream extends Writable {
   filePath: FilePath;
   options: ?FileOptions;
   buffer: Buffer;
+
   constructor(fs: FileSystem, filePath: FilePath, options: ?FileOptions) {
-    super();
+    super({emitClose: true, autoDestroy: true});
     this.fs = fs;
     this.filePath = filePath;
     this.options = options;
@@ -661,10 +662,10 @@ class WriteStream extends Writable {
   }
 
   _final(callback: (error?: Error) => void) {
-    this.fs.writeFile(this.filePath, this.buffer, this.options).then(
-      () => callback(),
-      err => callback(err),
-    );
+    this.fs
+      .writeFile(this.filePath, this.buffer, this.options)
+      .then(callback)
+      .catch(callback);
   }
 
   get bytesWritten() {
diff --git a/packages/core/fs/src/NodeFS.js b/packages/core/fs/src/NodeFS.js
index b52eb3274bc..9524b865e25 100644
--- a/packages/core/fs/src/NodeFS.js
+++ b/packages/core/fs/src/NodeFS.js
@@ -43,7 +43,10 @@ export class NodeFS implements FileSystem {
 
   createWriteStream(filePath: string, options: any): WriteStream {
     let tmpFilePath = getTempFilePath(filePath);
-    let stream = fs.createWriteStream(tmpFilePath, options);
+    let stream = fs.createWriteStream(tmpFilePath, {
+      ...options,
+      emitClose: true,
+    });
     stream.on('close', () => fs.renameSync(tmpFilePath, filePath));
     return stream;
   }
diff --git a/packages/reporters/bundle-analyzer/src/BundleAnalyzerReporter.js b/packages/reporters/bundle-analyzer/src/BundleAnalyzerReporter.js
index f520343ab0d..7ba8c310374 100644
--- a/packages/reporters/bundle-analyzer/src/BundleAnalyzerReporter.js
+++ b/packages/reporters/bundle-analyzer/src/BundleAnalyzerReporter.js
@@ -22,7 +22,9 @@ export default new Reporter({
       Array<NamedBundle>,
     > = new DefaultMap(() => []);
     for (let bundle of event.bundleGraph.getBundles()) {
-      bundlesByTarget.get(bundle.target.name).push(bundle);
+      if (!bundle.isInline) {
+        bundlesByTarget.get(bundle.target.name).push(bundle);
+      }
     }
 
     let reportsDir = path.join(options.projectRoot, 'parcel-bundle-reports');