diff --git a/pkgs/by-name/sa/safestringlib/package.nix b/pkgs/by-name/sa/safestringlib/package.nix
index ac049eb4a97c..911e981082f9 100644
--- a/pkgs/by-name/sa/safestringlib/package.nix
+++ b/pkgs/by-name/sa/safestringlib/package.nix
@@ -26,6 +26,7 @@ stdenv.mkDerivation {
 
   cmakeFlags = [
     (lib.cmakeBool "BUILD_UNITTESTS" true)
+    "-DCMAKE_POLICY_VERSION_MINIMUM=3.5"
   ];
 
   patches = [