diff --git a/pkgs/development/libraries/science/networking/ns-3/default.nix b/pkgs/development/libraries/science/networking/ns-3/default.nix
index fa6e5e48f846..e71e6f2a7ed6 100644
--- a/pkgs/development/libraries/science/networking/ns-3/default.nix
+++ b/pkgs/development/libraries/science/networking/ns-3/default.nix
@@ -1,5 +1,4 @@
 { stdenv
-, breakpointHook
 , fetchFromGitLab
 , python
 , libxml2
@@ -79,7 +78,7 @@ stdenv.mkDerivation rec {
     sqlite.dev
     gsl
     boost
-    root
+    root # provides cppyy
     glib.out
     glib.dev
     libpcap