diff --git a/overlay/readsb.nix b/overlay/readsb.nix
index 6c8b9973..44cc26ed 100644
--- a/overlay/readsb.nix
+++ b/overlay/readsb.nix
@@ -10,8 +10,9 @@ stdenv.mkDerivation rec {
   src = fetchFromGitHub {
     owner = "Mictronics";
     repo = name;
-    rev = "dev";
-    sha256 = "03hq9bjg9p6wysys7p0l3hzlfwzbp74k50yjd2n9lg3v1yc4vccl";
+    # branch "dev" as of 2021-12-10
+    rev = "b6c1bebc77d80a9366e31c13c73eea95e7a9296a";
+    sha256 = "0vg37cngbvahwb8wc6j5i605d8fn4ck0szy13xzw5b3q61aqvaqv";
   };
 
   nativeBuildInputs = [