diff --git a/flake.nix b/flake.nix
--- a/flake.nix
+++ b/flake.nix
@@ -329,6 +329,10 @@
               ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
                 pkgs.darwin.cctools
               ];
+          }
+          // pkgs.lib.optionalAttrs pkgs.stdenv.isDarwin {
+            # Point cargo's linker at the nix cc-wrapper so NIX_LDFLAGS applies.
+            "CARGO_TARGET_${pkgs.lib.toUpper (builtins.replaceStrings ["-"] ["_"] pkgs.stdenv.hostPlatform.rust.rustcTarget)}_LINKER" = "${pkgs.pkgsStatic.stdenv.cc.targetPrefix}cc";
           });
     in {
       default = staticShell {