diff --git a/modules/actions/serveHTMLModule.js b/modules/actions/serveHTMLModule.js
index 8d0cd00..0d9ffef 100644
--- a/modules/actions/serveHTMLModule.js
+++ b/modules/actions/serveHTMLModule.js
@@ -20,7 +20,7 @@ function serveHTMLModule(req, res) {
       .set({
         'Content-Length': Buffer.byteLength(code),
         'Content-Type': getContentTypeHeader(req.entry.contentType),
-        'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+        'Cache-Control': 'public, max-age=31536000', // 1 year
         ETag: etag(code),
         'Cache-Tag': 'file, html-file, html-module'
       })
diff --git a/modules/actions/serveJavaScriptModule.js b/modules/actions/serveJavaScriptModule.js
index 45e38ee..419416a 100644
--- a/modules/actions/serveJavaScriptModule.js
+++ b/modules/actions/serveJavaScriptModule.js
@@ -14,7 +14,7 @@ function serveJavaScriptModule(req, res) {
       .set({
         'Content-Length': Buffer.byteLength(code),
         'Content-Type': getContentTypeHeader(req.entry.contentType),
-        'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+        'Cache-Control': 'public, max-age=31536000', // 1 year
         ETag: etag(code),
         'Cache-Tag': 'file, js-file, js-module'
       })
diff --git a/modules/actions/serveMetadata.js b/modules/actions/serveMetadata.js
index 5c44c8c..8eb8c35 100644
--- a/modules/actions/serveMetadata.js
+++ b/modules/actions/serveMetadata.js
@@ -35,7 +35,7 @@ function serveMetadata(req, res) {
 
   res
     .set({
-      'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+      'Cache-Control': 'public, max-age=31536000', // 1 year
       'Cache-Tag': 'meta'
     })
     .send(metadata);
diff --git a/modules/actions/serveStaticFile.js b/modules/actions/serveStaticFile.js
index 32c66ee..902fad8 100644
--- a/modules/actions/serveStaticFile.js
+++ b/modules/actions/serveStaticFile.js
@@ -15,7 +15,7 @@ function serveStaticFile(req, res) {
     .set({
       'Content-Length': req.entry.size,
       'Content-Type': getContentTypeHeader(req.entry.contentType),
-      'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+      'Cache-Control': 'public, max-age=31536000', // 1 year
       'Last-Modified': req.entry.lastModified,
       ETag: etag(req.entry.content),
       'Cache-Tag': tags.join(', ')
diff --git a/modules/middleware/fetchPackage.js b/modules/middleware/fetchPackage.js
index a4cdb71..12edc1e 100644
--- a/modules/middleware/fetchPackage.js
+++ b/modules/middleware/fetchPackage.js
@@ -92,7 +92,7 @@ function filenameRedirect(req, res) {
   // and URLs resolve correctly.
   res
     .set({
-      'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+      'Cache-Control': 'public, max-age=31536000', // 1 year
       'Cache-Tag': 'redirect, filename-redirect'
     })
     .redirect(
diff --git a/modules/middleware/findFile.js b/modules/middleware/findFile.js
index 6664bdf..615741d 100644
--- a/modules/middleware/findFile.js
+++ b/modules/middleware/findFile.js
@@ -12,7 +12,7 @@ function indexRedirect(req, res, entry) {
   // resolve correctly.
   res
     .set({
-      'Cache-Control': 'public, max-age=31536000, immutable', // 1 year
+      'Cache-Control': 'public, max-age=31536000', // 1 year
       'Cache-Tag': 'redirect, index-redirect'
     })
     .redirect(
@@ -94,24 +94,26 @@ function searchEntries(tarballStream, entryName, wantsIndex) {
 
         const chunks = [];
 
-        stream.on('data', chunk => chunks.push(chunk)).on('end', () => {
-          const content = Buffer.concat(chunks);
+        stream
+          .on('data', chunk => chunks.push(chunk))
+          .on('end', () => {
+            const content = Buffer.concat(chunks);
 
-          // Set some extra properties for files that we will
-          // need to serve them and for ?meta listings.
-          entry.contentType = getContentType(entry.name);
-          entry.integrity = getIntegrity(content);
-          entry.lastModified = header.mtime.toUTCString();
-          entry.size = content.length;
+            // Set some extra properties for files that we will
+            // need to serve them and for ?meta listings.
+            entry.contentType = getContentType(entry.name);
+            entry.integrity = getIntegrity(content);
+            entry.lastModified = header.mtime.toUTCString();
+            entry.size = content.length;
 
-          // Set the content only for the foundEntry and
-          // discard the buffer for all others.
-          if (entry === foundEntry) {
-            entry.content = content;
-          }
+            // Set the content only for the foundEntry and
+            // discard the buffer for all others.
+            if (entry === foundEntry) {
+              entry.content = content;
+            }
 
-          next();
-        });
+            next();
+          });
       });
   });
 }