diff --git a/pkgs/tools/filesystems/sasquatch/default.nix b/pkgs/tools/filesystems/sasquatch/default.nix
index 238223c4981e..017fda14cc65 100644
--- a/pkgs/tools/filesystems/sasquatch/default.nix
+++ b/pkgs/tools/filesystems/sasquatch/default.nix
@@ -43,6 +43,9 @@ stdenv.mkDerivation rec {
   patchFlags = [ "-p0" ];
 
   postPatch = ''
+    # Drop blanket -Werror to avoid build failure on fresh toolchains
+    # like gcc-11.
+    substituteInPlace squashfs-tools/Makefile --replace ' -Werror' ' '
     cd squashfs-tools
   '';