diff --git a/pkgs/tools/networking/cjdns/default.nix b/pkgs/tools/networking/cjdns/default.nix
index f9dc3de7735..df94de882be 100644
--- a/pkgs/tools/networking/cjdns/default.nix
+++ b/pkgs/tools/networking/cjdns/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation {
     # for flock
     stdenv.lib.optional stdenv.isLinux utillinux;
 
-  CFLAGS = "-O2";
+  CFLAGS = "-O2 -Wno-error=stringop-truncation";
   buildPhase =
     stdenv.lib.optionalString stdenv.isAarch32 "Seccomp_NO=1 "
     + "bash do";