diff --git a/cli/test/smokehouse/test-definitions/byte-efficiency.js b/cli/test/smokehouse/test-definitions/byte-efficiency.js
index c25e34690c8e..01f057bbd551 100644
--- a/cli/test/smokehouse/test-definitions/byte-efficiency.js
+++ b/cli/test/smokehouse/test-definitions/byte-efficiency.js
@@ -187,25 +187,25 @@ const expectations = {
           items: [
             {
               url: 'http://localhost:10200/byte-efficiency/script.js',
-              wastedBytes: '46039 +/- 100',
+              wastedBytes: '45816 +/- 100',
               wastedPercent: '87 +/- 5',
             },
             {
               // /some-custom-url.js,
               url: 'inline: \n  function unusedFunction() {\n    // U…',
-              wastedBytes: '6690 +/- 100',
+              wastedBytes: '6630 +/- 100',
               wastedPercent: '99.6 +/- 0.1',
             },
             {
               url: 'inline: \n  // Used block #1\n  // FILLER DATA JU…',
-              wastedBytes: '6569 +/- 100',
+              wastedBytes: '6510 +/- 100',
               wastedPercent: 100,
             },
             {
               url: 'http://localhost:10200/byte-efficiency/bundle.js',
               totalBytes: '12962 +/- 1000',
-              wastedBytes: '2349 +/- 100',
-              wastedPercent: '19 +/- 5',
+              wastedBytes: '2303 +/- 100',
+              wastedPercent: '18 +/- 5',
             },
           ],
         },
diff --git a/core/audits/byte-efficiency/unminified-javascript.js b/core/audits/byte-efficiency/unminified-javascript.js
index 821bfc7845e1..c80bd6c20db1 100644
--- a/core/audits/byte-efficiency/unminified-javascript.js
+++ b/core/audits/byte-efficiency/unminified-javascript.js
@@ -7,7 +7,7 @@
 import {ByteEfficiencyAudit} from './byte-efficiency-audit.js';
 import * as i18n from '../../lib/i18n/i18n.js';
 import {computeJSTokenLength as computeTokenLength} from '../../lib/minification-estimator.js';
-import {estimateTransferSize, getRequestForScript, isInline} from '../../lib/script-helpers.js';
+import {estimateCompressedContentSize, getRequestForScript, isInline} from '../../lib/script-helpers.js';
 import {Util} from '../../../shared/util.js';
 
 const UIStrings = {
@@ -58,7 +58,7 @@ class UnminifiedJavaScript extends ByteEfficiencyAudit {
     const contentLength = scriptContent.length;
     const totalTokenLength = computeTokenLength(scriptContent);
 
-    const totalBytes = estimateTransferSize(networkRecord, contentLength, 'Script');
+    const totalBytes = estimateCompressedContentSize(networkRecord, contentLength, 'Script');
     const wastedRatio = 1 - totalTokenLength / contentLength;
     const wastedBytes = Math.round(totalBytes * wastedRatio);
 
diff --git a/core/test/audits/byte-efficiency/unminified-javascript-test.js b/core/test/audits/byte-efficiency/unminified-javascript-test.js
index 11e0b3d4eb1d..2183b11bc069 100644
--- a/core/test/audits/byte-efficiency/unminified-javascript-test.js
+++ b/core/test/audits/byte-efficiency/unminified-javascript-test.js
@@ -14,6 +14,8 @@ const KB = 1024;
 const resourceType = 'Script';
 describe('Page uses optimized responses', () => {
   it('fails when given unminified scripts', () => {
+    const responseHeaders = [{name: 'Content-Encoding'}];
+    const commonRecord = {resourceType, responseHeaders};
     const auditResult = UnminifiedJavascriptAudit.audit_({
       URL: {finalDisplayedUrl: 'https://www.example.com'},
       Scripts: [
@@ -59,10 +61,10 @@ describe('Page uses optimized responses', () => {
         },
       ].map(createScript),
     }, [
-      {requestId: '123.1', url: 'foo.js', transferSize: 20 * KB, resourceType},
-      {requestId: '123.2', url: 'other.js', transferSize: 50 * KB, resourceType},
-      {requestId: '123.3', url: 'valid-ish.js', transferSize: 100 * KB, resourceType},
-      {requestId: '123.4', url: 'invalid.js', transferSize: 100 * KB, resourceType},
+      {requestId: '123.1', url: 'foo.js', transferSize: 20 * KB, ...commonRecord},
+      {requestId: '123.2', url: 'other.js', transferSize: 50 * KB, ...commonRecord},
+      {requestId: '123.3', url: 'valid-ish.js', transferSize: 100 * KB, ...commonRecord},
+      {requestId: '123.4', url: 'invalid.js', transferSize: 100 * KB, ...commonRecord},
     ]);
 
     const results = auditResult.items.map(item => Object.assign(item, {
diff --git a/core/test/results/sample_v2.json b/core/test/results/sample_v2.json
index 944eaabcd608..6094b082f427 100644
--- a/core/test/results/sample_v2.json
+++ b/core/test/results/sample_v2.json
@@ -4453,7 +4453,7 @@
       "scoreDisplayMode": "metricSavings",
       "numericValue": 1200,
       "numericUnit": "millisecond",
-      "displayValue": "Potential savings of 82 KiB",
+      "displayValue": "Potential savings of 81 KiB",
       "warnings": [],
       "metricSavings": {
         "FCP": 0,
@@ -4481,13 +4481,13 @@
         "items": [
           {
             "url": "http://localhost:10200/dobetterweb/third_party/aggressive-promise-polyfill.js",
-            "totalBytes": 166550,
-            "wastedBytes": 83568,
+            "totalBytes": 166320,
+            "wastedBytes": 83453,
             "wastedPercent": 50.176166426166425
           }
         ],
         "overallSavingsMs": 1200,
-        "overallSavingsBytes": 83568,
+        "overallSavingsBytes": 83453,
         "sortedBy": [
           "wastedBytes"
         ],
@@ -10443,7 +10443,7 @@
       "core/lib/i18n/i18n.js | displayValueByteSavings": [
         {
           "values": {
-            "wastedBytes": 83568
+            "wastedBytes": 83453
           },
           "path": "audits[unminified-javascript].displayValue"
         },