diff --git a/pkgs/os-specific/bsd/freebsd/pkgs/libsysdecode.nix b/pkgs/os-specific/bsd/freebsd/pkgs/libsysdecode.nix
index 9d27a1577031..f2774d37b88c 100644
--- a/pkgs/os-specific/bsd/freebsd/pkgs/libsysdecode.nix
+++ b/pkgs/os-specific/bsd/freebsd/pkgs/libsysdecode.nix
@@ -6,8 +6,12 @@ mkDerivation {
     "libexec/rtld-elf"
   ];
 
+  NIX_CFLAGS_COMPILE = [
+    "-Wno-unterminated-string-initialization"
+  ];
+
   preBuild = ''
-    sed -E -i -e "s|..INCLUDEDIR.|${stdenv.cc.libc}/include|g" $BSDSRCDIR/lib/libsysdecode/Makefile
+    sed -E -i -e "s|\\$\\{INCLUDEDIR\\}|${stdenv.cc.libc}/include|g" $BSDSRCDIR/lib/libsysdecode/Makefile
   '';
 
   MK_TESTS = "no";