diff --git a/bin/build.sh b/bin/build.sh
index 19e3149..386bcf0 100755
--- a/bin/build.sh
+++ b/bin/build.sh
@@ -60,7 +60,7 @@ git archive --format tar "$RELEASE" | (cd "$DEST"; tar xv)
 
 cd "$DEST"
 
-zip -r "$TARGET" *
+zip -1 -r "$TARGET" *
 
 cd /
 rm -rf "$DEST"
diff --git a/bootstrap.js b/bootstrap.js
index f233617..400cde6 100644
--- a/bootstrap.js
+++ b/bootstrap.js
@@ -3,7 +3,7 @@
 // The onOpenWindow event handler was slightly modified to be compatible with standard Firefox.
 
 var browser = browser || chrome
-browser.browserAction.onClicked.addListener((tab) => showTracerWindow());
+browser.action.onClicked.addListener((tab) => showTracerWindow());
 
 var tracerWindow = null;
 
diff --git a/manifest.json b/manifest.json
index f797175..52402e4 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,8 +1,8 @@
 {
   "name": "SAML-tracer",
   "description": "A debugger for viewing SAML messages",
-  "author": "Olav Morken, Jaime Perez, Thijs Kinkhorst, Jan Köhler",
-  "manifest_version": 2,
+  "author": "Olav Morken, Jaime Perez, Thijs Kinkhorst, Jan Köhler, Tim van Dijen",
+  "manifest_version": 3,
   "version": "1.8.0",
   "homepage_url": "https://github.com/SimpleSAMLphp/SAML-tracer",
   "icons": {
@@ -13,14 +13,16 @@
     "128": "src/resources/images/icon128.png"
   },
   "permissions": [
-    "webRequest",
-    "webRequestBlocking",
+    "webRequest"
+  ],
+  "host_permissions": [
     "<all_urls>"
   ],
   "background": {
+    "service_worker": "bootstrap.js",
     "scripts": ["bootstrap.js"]
   },
-  "browser_action": {
+  "action": {
     "default_icon": {
       "16": "src/resources/images/icon16.png",
       "32": "src/resources/images/icon32.png",
@@ -29,8 +31,14 @@
       "128": "src/resources/images/icon128.png"
     }
   },
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "{d3e01ff2-9a3a-4007-8f6e-7acd9a5de263}",
+      "strict_min_version": "121.0"
+    }
+  },
   "commands": {
-    "_execute_browser_action": {
+    "_execute_action": {
       "suggested_key": {
         "default": "Alt+Shift+S"
       },
diff --git a/src/SAMLTrace.js b/src/SAMLTrace.js
index c3e41b7..1912c71 100644
--- a/src/SAMLTrace.js
+++ b/src/SAMLTrace.js
@@ -905,19 +905,19 @@ SAMLTrace.TraceWindow.init = function() {
   browser.webRequest.onBeforeRequest.addListener(
     traceWindow.saveNewRequest,
     {urls: ["<all_urls>"]},
-    ["blocking", "requestBody"]
+    ["requestBody"]
   );
 
   browser.webRequest.onBeforeSendHeaders.addListener(
     traceWindow.attachHeadersToRequest,
     {urls: ["<all_urls>"]},
-    ['blocking', 'requestHeaders', browser.webRequest.OnBeforeSendHeadersOptions.EXTRA_HEADERS].filter(Boolean)
+    ['requestHeaders', browser.webRequest.OnBeforeSendHeadersOptions.EXTRA_HEADERS].filter(Boolean)
   );
 
   browser.webRequest.onHeadersReceived.addListener(
     traceWindow.attachResponseToRequest,
     {urls: ["<all_urls>"]},
-    ['blocking', 'responseHeaders', browser.webRequest.OnHeadersReceivedOptions.EXTRA_HEADERS].filter(Boolean)
+    ['responseHeaders', browser.webRequest.OnHeadersReceivedOptions.EXTRA_HEADERS].filter(Boolean)
   );
 };