diff --git a/src/source/raster_dem_tile_source.js b/src/source/raster_dem_tile_source.js
index 5e7a8e6cfd6..31daad032b0 100644
--- a/src/source/raster_dem_tile_source.js
+++ b/src/source/raster_dem_tile_source.js
@@ -32,7 +32,7 @@ class RasterDEMTileSource extends RasterTileSource implements Source {
         const url = this.map._requestManager.normalizeTileURL(tile.tileID.canonical.url(this.tiles, this.scheme), false, this.tileSize);
         tile.request = getImage(this.map._requestManager.transformRequest(url, ResourceType.Tile), imageLoaded.bind(this));
 
-        function imageLoaded(err, img) {
+        function imageLoaded(err, img, cacheControl, expires) {
             delete tile.request;
             if (tile.aborted) {
                 tile.state = 'unloaded';
@@ -41,9 +41,7 @@ class RasterDEMTileSource extends RasterTileSource implements Source {
                 tile.state = 'errored';
                 callback(err);
             } else if (img) {
-                if (this.map._refreshExpiredTiles) tile.setExpiryData(img);
-                delete (img: any).cacheControl;
-                delete (img: any).expires;
+                if (this.map._refreshExpiredTiles) tile.setExpiryData({cacheControl, expires});
                 const transfer = window.ImageBitmap && img instanceof window.ImageBitmap && offscreenCanvasSupported();
                 // DEMData uses 1px padding. Handle cases with image buffer of 1 and 2 pxs, the rest assume default buffer 0
                 // in order to keep the previous implementation working (no validation against tileSize).
diff --git a/src/source/raster_tile_source.js b/src/source/raster_tile_source.js
index 874cd9e1dbb..cfc7ab4b712 100644
--- a/src/source/raster_tile_source.js
+++ b/src/source/raster_tile_source.js
@@ -112,7 +112,7 @@ class RasterTileSource extends Evented implements Source {
     loadTile(tile: Tile, callback: Callback<void>) {
         const use2x = browser.devicePixelRatio >= 2;
         const url = this.map._requestManager.normalizeTileURL(tile.tileID.canonical.url(this.tiles, this.scheme), use2x, this.tileSize);
-        tile.request = getImage(this.map._requestManager.transformRequest(url, ResourceType.Tile), (err, img) => {
+        tile.request = getImage(this.map._requestManager.transformRequest(url, ResourceType.Tile), (err, img, cacheControl, expires) => {
             delete tile.request;
 
             if (tile.aborted) {
@@ -122,9 +122,7 @@ class RasterTileSource extends Evented implements Source {
                 tile.state = 'errored';
                 callback(err);
             } else if (img) {
-                if (this.map._refreshExpiredTiles) tile.setExpiryData(img);
-                delete (img: any).cacheControl;
-                delete (img: any).expires;
+                if (this.map._refreshExpiredTiles) tile.setExpiryData({cacheControl, expires});
 
                 const context = this.map.painter.context;
                 const gl = context.gl;
diff --git a/src/util/ajax.js b/src/util/ajax.js
index de5108c4824..67b24505ab6 100644
--- a/src/util/ajax.js
+++ b/src/util/ajax.js
@@ -7,7 +7,6 @@ import config from './config.js';
 import assert from 'assert';
 import {cacheGet, cachePut} from './tile_request_cache.js';
 import webpSupported from './webp_supported.js';
-import offscreenCanvasSupported from './offscreen_canvas_supported.js';
 
 import type {Callback} from '../types/callback.js';
 import type {Cancelable} from '../types/cancelable.js';
@@ -273,7 +272,7 @@ function sameOrigin(url) {
 
 const transparentPngUrl = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQYV2NgAAIAAAUAAarVyFEAAAAASUVORK5CYII=';
 
-function arrayBufferToImage(data: ArrayBuffer, callback: (err: ?Error, image: ?HTMLImageElement) => void, cacheControl: ?string, expires: ?string) {
+function arrayBufferToImage(data: ArrayBuffer, callback: Callback<HTMLImageElement>) {
     const img: HTMLImageElement = new window.Image();
     const URL = window.URL;
     img.onload = () => {
@@ -287,12 +286,10 @@ function arrayBufferToImage(data: ArrayBuffer, callback: (err: ?Error, image: ?H
     };
     img.onerror = () => callback(new Error('Could not load image. Please make sure to use a supported image type such as PNG or JPEG. Note that SVGs are not supported.'));
     const blob: Blob = new window.Blob([new Uint8Array(data)], {type: 'image/png'});
-    (img: any).cacheControl = cacheControl;
-    (img: any).expires = expires;
     img.src = data.byteLength ? URL.createObjectURL(blob) : transparentPngUrl;
 }
 
-function arrayBufferToImageBitmap(data: ArrayBuffer, callback: (err: ?Error, image: ?ImageBitmap) => void) {
+function arrayBufferToImageBitmap(data: ArrayBuffer, callback: Callback<ImageBitmap>) {
     const blob: Blob = new window.Blob([new Uint8Array(data)], {type: 'image/png'});
     window.createImageBitmap(blob).then((imgBitmap) => {
         callback(null, imgBitmap);
@@ -308,7 +305,7 @@ export const resetImageRequestQueue = () => {
 };
 resetImageRequestQueue();
 
-export const getImage = function(requestParameters: RequestParameters, callback: Callback<HTMLImageElement | ImageBitmap>): Cancelable {
+export const getImage = function(requestParameters: RequestParameters, callback: ResponseCallback<HTMLImageElement | ImageBitmap>): Cancelable {
     if (webpSupported.supported) {
         if (!requestParameters.headers) {
             requestParameters.headers = {};
@@ -353,10 +350,10 @@ export const getImage = function(requestParameters: RequestParameters, callback:
         if (err) {
             callback(err);
         } else if (data) {
-            if (offscreenCanvasSupported()) {
-                arrayBufferToImageBitmap(data, callback);
+            if (window.createImageBitmap) {
+                arrayBufferToImageBitmap(data, (err, imgBitmap) => callback(err, imgBitmap, cacheControl, expires));
             } else {
-                arrayBufferToImage(data, callback, cacheControl, expires);
+                arrayBufferToImage(data, (err, img) => callback(err, img, cacheControl, expires));
             }
         }
     });
diff --git a/test/unit/util/ajax.test.js b/test/unit/util/ajax.test.js
index 887f81443f5..077264f2534 100644
--- a/test/unit/util/ajax.test.js
+++ b/test/unit/util/ajax.test.js
@@ -213,5 +213,59 @@ test('ajax', (t) => {
         window.server.respond();
     });
 
+    t.test('getImage retains cache control headers when using arrayBufferToImage', (t) => {
+        resetImageRequestQueue();
+
+        const headers = {
+            'Content-Type': 'image/webp',
+            'Cache-Control': 'max-age=43200,s-maxage=604800',
+            'Expires': 'Wed, 21 Oct 2015 07:28:00 GMT'
+        };
+
+        window.server.respondWith(request => request.respond(200, headers, ''));
+
+        // jsdom doesn't call image onload; fake it https://github.com/jsdom/jsdom/issues/1816
+        window.Image = class {
+            set src(src) {
+                setTimeout(() => {
+                    if (this.onload) this.onload();
+                });
+            }
+        };
+
+        getImage({url: ''}, (err, img, cacheControl, expires) => {
+            if (err) t.fail();
+            t.equals(cacheControl, headers['Cache-Control']);
+            t.equals(expires, headers['Expires']);
+            t.end();
+        });
+
+        window.server.respond();
+    });
+
+    t.test('getImage retains cache control headers when using arrayBufferToImageBitmap', (t) => {
+        resetImageRequestQueue();
+
+        const headers = {
+            'Content-Type': 'image/webp',
+            'Cache-Control': 'max-age=43200,s-maxage=604800',
+            'Expires': 'Wed, 21 Oct 2015 07:28:00 GMT'
+        };
+
+        window.server.respondWith(request => request.respond(200, headers, ''));
+
+        // jsdom doesn't support createImageBitmap; fake it
+        window.createImageBitmap = () => Promise.resolve();
+
+        getImage({url: ''}, (err, img, cacheControl, expires) => {
+            if (err) t.fail();
+            t.equals(cacheControl, headers['Cache-Control']);
+            t.equals(expires, headers['Expires']);
+            t.end();
+        });
+
+        window.server.respond();
+    });
+
     t.end();
 });