diff --git a/src/addon/mod/book/providers/book.ts b/src/addon/mod/book/providers/book.ts
index d9cf9cd8c..6944ea73e 100644
--- a/src/addon/mod/book/providers/book.ts
+++ b/src/addon/mod/book/providers/book.ts
@@ -125,7 +125,7 @@ export class AddonModBookProvider {
             promise = this.filepoolProvider.downloadUrl(siteId, indexUrl, false, AddonModBookProvider.COMPONENT, moduleId);
         } else {
             // We return the live URL.
-            return Promise.resolve(this.sitesProvider.getCurrentSite().fixPluginfileURL(indexUrl));
+            return this.sitesProvider.getCurrentSite().checkAndFixPluginfileURL(indexUrl);
         }
 
         return promise.then((url) => {
diff --git a/src/addon/mod/imscp/providers/imscp.ts b/src/addon/mod/imscp/providers/imscp.ts
index 26591f768..58667b135 100644
--- a/src/addon/mod/imscp/providers/imscp.ts
+++ b/src/addon/mod/imscp/providers/imscp.ts
@@ -245,7 +245,7 @@ export class AddonModImscpProvider {
 
                 if (indexUrl) {
                     return this.sitesProvider.getSite(siteId).then((site) => {
-                        return site.fixPluginfileURL(indexUrl);
+                        return site.checkAndFixPluginfileURL(indexUrl);
                     });
                 }
             }
diff --git a/src/addon/mod/page/providers/helper.ts b/src/addon/mod/page/providers/helper.ts
index 7b2f1852e..43887b52a 100644
--- a/src/addon/mod/page/providers/helper.ts
+++ b/src/addon/mod/page/providers/helper.ts
@@ -76,7 +76,7 @@ export class AddonModPageHelperProvider {
                 AddonModPageProvider.COMPONENT, moduleId);
         } else {
             // We return the live URL.
-            promise = Promise.resolve(this.sitesProvider.getCurrentSite().fixPluginfileURL(indexUrl));
+            promise = this.sitesProvider.getCurrentSite().checkAndFixPluginfileURL(indexUrl);
         }
 
         return promise.then((url) => {
diff --git a/src/addon/mod/resource/providers/helper.ts b/src/addon/mod/resource/providers/helper.ts
index df5dfc870..401783103 100644
--- a/src/addon/mod/resource/providers/helper.ts
+++ b/src/addon/mod/resource/providers/helper.ts
@@ -82,7 +82,7 @@ export class AddonModResourceHelperProvider {
             // Error getting directory, there was an error downloading or we're in browser. Return online URL.
             if (this.appProvider.isOnline() && mainFile.fileurl) {
                 // This URL is going to be injected in an iframe, we need this to make it work.
-                return Promise.resolve(this.sitesProvider.getCurrentSite().fixPluginfileURL(mainFile.fileurl));
+                return this.sitesProvider.getCurrentSite().checkAndFixPluginfileURL(mainFile.fileurl);
             }
 
             return Promise.reject(null);
diff --git a/src/classes/site.ts b/src/classes/site.ts
index a038bb3e0..e1f0fb458 100644
--- a/src/classes/site.ts
+++ b/src/classes/site.ts
@@ -230,6 +230,8 @@ export class CoreSite {
     protected ongoingRequests: { [cacheId: string]: Promise<any> } = {};
     protected requestQueue: RequestQueueItem[] = [];
     protected requestQueueTimeout = null;
+    protected tokenPluginFileWorks: boolean;
+    protected tokenPluginFileWorksPromise: Promise<boolean>;
 
     /**
      * Create a site.
@@ -1226,6 +1228,18 @@ export class CoreSite {
         return this.db.execute(sql, [key + '%']);
     }
 
+    /**
+     * Check if tokenpluginfile can be used, and fix the URL afterwards.
+     *
+     * @param url The url to be fixed.
+     * @return Promise resolved with the fixed URL.
+     */
+    checkAndFixPluginfileURL(url: string): Promise<string> {
+        return this.checkTokenPluginFile(url).then(() => {
+            return this.fixPluginfileURL(url);
+        });
+    }
+
     /**
      * Generic function for adding the wstoken to Moodle urls and for pointing to the correct script.
      * Uses CoreUtilsProvider.fixPluginfileURL, passing site's token.
@@ -1234,7 +1248,10 @@ export class CoreSite {
      * @return Fixed URL.
      */
     fixPluginfileURL(url: string): string {
-        return this.urlUtils.fixPluginfileURL(url, this.token, this.siteUrl);
+        const accessKey = this.tokenPluginFileWorks || typeof this.tokenPluginFileWorks == 'undefined' ?
+                this.infos && this.infos.userprivateaccesskey : undefined;
+
+        return this.urlUtils.fixPluginfileURL(url, this.token, this.siteUrl, accessKey);
     }
 
     /**
@@ -1886,4 +1903,44 @@ export class CoreSite {
 
         return expirationDelay;
     }
+
+    /*
+     * Check if tokenpluginfile script works in the site.
+     *
+     * @param url URL to check.
+     * @return Promise resolved with boolean: whether it works or not.
+     */
+    checkTokenPluginFile(url: string): Promise<boolean> {
+        if (!this.infos || !this.infos.userprivateaccesskey) {
+            // No access key, cannot use tokenpluginfile.
+            return Promise.resolve(false);
+        } else if (typeof this.tokenPluginFileWorks != 'undefined') {
+            // Already checked.
+            return Promise.resolve(this.tokenPluginFileWorks);
+        } else if (this.tokenPluginFileWorksPromise) {
+            // Check ongoing, use the same promise.
+            return this.tokenPluginFileWorksPromise;
+        } else if (!this.appProvider.isOnline()) {
+            // Not online, cannot check it. Assume it's working, but don't save the result.
+            return Promise.resolve(true);
+        } else if (!this.urlUtils.isPluginFileUrl(url)) {
+            // Not a pluginfile URL, ignore it.
+            return Promise.resolve(false);
+        }
+
+        url = this.fixPluginfileURL(url);
+
+        this.tokenPluginFileWorksPromise = this.wsProvider.performHead(url).then((result) => {
+            return result.ok;
+        }).catch((error) => {
+            // Error performing head request.
+            return false;
+        }).then((result) => {
+            this.tokenPluginFileWorks = result;
+
+            return result;
+        });
+
+        return this.tokenPluginFileWorksPromise;
+    }
 }
diff --git a/src/core/course/providers/helper.ts b/src/core/course/providers/helper.ts
index f4b2f8bcb..d529e5187 100644
--- a/src/core/course/providers/helper.ts
+++ b/src/core/course/providers/helper.ts
@@ -569,21 +569,22 @@ export class CoreCourseHelperProvider {
             if (this.fileHelper.shouldOpenInBrowser(mainFile)) {
                 if (this.appProvider.isOnline()) {
                     // Open in browser.
-                    let fixedUrl = site.fixPluginfileURL(fileUrl).replace('&offline=1', '');
-                    // Remove forcedownload when followed by another param.
-                    fixedUrl = fixedUrl.replace(/forcedownload=\d+&/, '');
-                    // Remove forcedownload when not followed by any param.
-                    fixedUrl = fixedUrl.replace(/[\?|\&]forcedownload=\d+/, '');
+                    return site.checkAndFixPluginfileURL(fileUrl).then((fixedUrl) => {
+                        fixedUrl = fixedUrl.replace('&offline=1', '');
+                        // Remove forcedownload when followed by another param.
+                        fixedUrl = fixedUrl.replace(/forcedownload=\d+&/, '');
+                        // Remove forcedownload when not followed by any param.
+                        fixedUrl = fixedUrl.replace(/[\?|\&]forcedownload=\d+/, '');
 
-                    this.utils.openInBrowser(fixedUrl);
+                        this.utils.openInBrowser(fixedUrl);
 
-                    if (this.fileProvider.isAvailable()) {
-                        // Download the file if needed (file outdated or not downloaded).
-                        // Download will be in background, don't return the promise.
-                        this.downloadModule(module, courseId, component, componentId, files, siteId);
-                    }
+                        if (this.fileProvider.isAvailable()) {
+                            // Download the file if needed (file outdated or not downloaded).
+                            // Download will be in background, don't return the promise.
+                            this.downloadModule(module, courseId, component, componentId, files, siteId);
+                        }
+                    });
 
-                    return;
                 } else {
                     // Not online, get the offline file. It will fail if not found.
                     return this.filepoolProvider.getInternalUrlByUrl(siteId, fileUrl).then((path) => {
@@ -664,7 +665,8 @@ export class CoreCourseHelperProvider {
             };
 
         return this.sitesProvider.getSite(siteId).then((site) => {
-            const fixedUrl = site.fixPluginfileURL(fileUrl);
+            return site.checkAndFixPluginfileURL(fileUrl);
+        }).then((fixedUrl) => {
             result.fixedUrl = fixedUrl;
 
             if (this.fileProvider.isAvailable()) {
diff --git a/src/providers/file-helper.ts b/src/providers/file-helper.ts
index 1c082111e..a9fc44c1e 100644
--- a/src/providers/file-helper.ts
+++ b/src/providers/file-helper.ts
@@ -119,7 +119,8 @@ export class CoreFileHelperProvider {
         siteId = siteId || this.sitesProvider.getCurrentSiteId();
 
         return this.sitesProvider.getSite(siteId).then((site) => {
-            const fixedUrl = site.fixPluginfileURL(fileUrl);
+            return site.checkAndFixPluginfileURL(fileUrl);
+        }).then((fixedUrl) => {
 
             if (this.fileProvider.isAvailable()) {
                 let promise;
diff --git a/src/providers/filepool.ts b/src/providers/filepool.ts
index f2e8afdac..db8b0f9ea 100644
--- a/src/providers/filepool.ts
+++ b/src/providers/filepool.ts
@@ -1321,7 +1321,7 @@ export class CoreFilepoolProvider {
      */
     protected fixPluginfileURL(siteId: string, fileUrl: string): Promise<string> {
         return this.sitesProvider.getSite(siteId).then((site) => {
-            return site.fixPluginfileURL(fileUrl);
+            return site.checkAndFixPluginfileURL(fileUrl);
         });
     }
 
@@ -1417,6 +1417,10 @@ export class CoreFilepoolProvider {
         // Decode URL.
         url = this.textUtils.decodeHTML(this.textUtils.decodeURIComponent(url));
 
+        // If site supports it, since 3.8 we use tokenpluginfile instead of pluginfile.
+        // For compatibility with files already downloaded, we need to use pluginfile to calculate the file ID.
+        url = url.replace(/\/tokenpluginfile\.php\/[^\/]+\//, '/webservice/pluginfile.php/');
+
         if (url.indexOf('/webservice/pluginfile') !== -1) {
             // Remove attributes that do not matter.
             this.urlAttributes.forEach((regex) => {
diff --git a/src/providers/utils/url.ts b/src/providers/utils/url.ts
index 2aa7e8ff5..600f84d5e 100644
--- a/src/providers/utils/url.ts
+++ b/src/providers/utils/url.ts
@@ -130,9 +130,10 @@ export class CoreUrlUtilsProvider {
      * @param url The url to be fixed.
      * @param token Token to use.
      * @param siteUrl The URL of the site the URL belongs to.
+     * @param accessKey User access key for tokenpluginfile.
      * @return Fixed URL.
      */
-    fixPluginfileURL(url: string, token: string, siteUrl: string): string {
+    fixPluginfileURL(url: string, token: string, siteUrl: string, accessKey?: string): string {
         if (!url) {
             return '';
         }
@@ -140,7 +141,7 @@ export class CoreUrlUtilsProvider {
         url = url.replace(/&amp;/g, '&');
 
         // First check if we need to fix this url or is already fixed.
-        if (url.indexOf('token=') != -1) {
+        if (!accessKey && url.indexOf('token=') != -1) {
             return url;
         }
 
@@ -149,7 +150,17 @@ export class CoreUrlUtilsProvider {
             return url;
         }
 
-        // Check if the URL already has params.
+        const hasSlashParams = !url.match(/[\&?]file=/);
+
+        if (accessKey && hasSlashParams) {
+            // We have the user access key, use tokenpluginfile.php.
+            // Do not use it without slash params, the URL doesn't work.
+            url = url.replace(/(\/webservice)?\/pluginfile\.php/, '/tokenpluginfile.php/' + accessKey);
+
+            return url;
+        }
+
+        // No access key, use pluginfile.php. Check if the URL already has params.
         if (url.match(/\?[^=]+=/)) {
             url += '&';
         } else {