diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index b95b0043324f..5f1e2af2d759 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -62,13 +62,13 @@
 
   firefox-devedition = buildMozillaMach rec {
     pname = "firefox-devedition";
-    version = "131.0b2";
+    version = "131.0b9";
     applicationName = "Mozilla Firefox Developer Edition";
     requireSigning = false;
     branding = "browser/branding/aurora";
     src = fetchurl {
       url = "mirror://mozilla/devedition/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "704d30f4c5d2a7cddda53f572551cc5fe49bc380388bda5c0eceac121c7d91ee616f586231a33539bb277aa4ea4e963a0d7f4d40f9738d4d30e4a3da75233d97";
+      sha512 = "f1f56bd121ecdf1f659ce85ea77a9b1abe983583081f6cadaaf4c57695148b481eed1ecfa7ac2d3449fbc1a0c8560a8a5665e309722a5fc5455df740cf639989";
     };
 
     meta = {