diff --git a/pkgs/os-specific/darwin/apple-source-releases/configd/default.nix b/pkgs/os-specific/darwin/apple-source-releases/configd/default.nix
index 3b8512cd89ce..998bc867e757 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/configd/default.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/configd/default.nix
@@ -21,7 +21,6 @@ appleDerivation' stdenv {
     NIX_CFLAGS_COMPILE = toString [
       "-ISystemConfiguration.framework/Headers"
       "-I${xnu}/Library/Frameworks/System.framework/Versions/B/PrivateHeaders"
-      "-D_DNS_SD_LIBDISPATCH" # Needed for DNSServiceSetDispatchQueue to be available
     ];
   };
 
diff --git a/pkgs/os-specific/darwin/apple-source-releases/mDNSResponder/default.nix b/pkgs/os-specific/darwin/apple-source-releases/mDNSResponder/default.nix
index 4082f5b760cf..0ba4caee6289 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/mDNSResponder/default.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/mDNSResponder/default.nix
@@ -4,6 +4,9 @@ appleDerivation' stdenvNoCC {
   dontBuild = true;
   installPhase = ''
     mkdir -p $out/include
-    cp mDNSShared/dns_sd.h $out/include
+    # TODO: Do this only for 765.50.9 once there is a way to apply version-specific
+    # logic in a source-release derivation.
+    substitute mDNSShared/dns_sd.h $out/include/dns_sd.h \
+      --replace '#define _DNS_SD_LIBDISPATCH 0' '#define _DNS_SD_LIBDISPATCH 1'
   '';
 }