diff --git a/pkgs/development/tools/parsing/flex-iputils/builder.sh b/pkgs/development/tools/parsing/flex-iputils/builder.sh
deleted file mode 100644
index 946301946ba..00000000000
--- a/pkgs/development/tools/parsing/flex-iputils/builder.sh
+++ /dev/null
@@ -1,10 +0,0 @@
-source $stdenv/setup
-
-installPhase() {
-   make install
-   cd $out/bin; ln -s flex lex
-   cd $out/lib; ln -s libfl.a libl.a
-}
-
-installPhase=installPhase
-genericBuild
diff --git a/pkgs/development/tools/parsing/flex-iputils/default.nix b/pkgs/development/tools/parsing/flex-iputils/default.nix
deleted file mode 100644
index c680f0f5c49..00000000000
--- a/pkgs/development/tools/parsing/flex-iputils/default.nix
+++ /dev/null
@@ -1,13 +0,0 @@
-{stdenv, fetchurl, yacc}:
-
-assert yacc != null;
-
-stdenv.mkDerivation {
-  name = "flex-2.5.4a";
-  builder = ./builder.sh;
-  src = fetchurl {
-    url = http://nix.cs.uu.nl/dist/tarballs/flex-2.5.4a.tar.gz;
-    md5 = "bd8753d0b22e1f4ec87a553a73021adf";
-  };
-  buildInputs = [yacc];
-}
diff --git a/pkgs/development/tools/parsing/flex-iputils/flex-new.nix b/pkgs/development/tools/parsing/flex-iputils/flex-new.nix
deleted file mode 100644
index 802f77a9ad6..00000000000
--- a/pkgs/development/tools/parsing/flex-iputils/flex-new.nix
+++ /dev/null
@@ -1,16 +0,0 @@
-# !!! this should be moved to default.nix eventually (but I delay
-# doing that since it would cause a rebuild of lots of stuff).
-
-{stdenv, fetchurl, yacc, m4}:
-
-assert yacc != null && m4 != null;
-
-stdenv.mkDerivation {
-  name = "flex-2.5.31";
-  src = fetchurl {
-    url = http://nix.cs.uu.nl/dist/tarballs/flex-2.5.31.tar.bz2;
-    md5 = "363dcc4afc917dc51306eb9d3de0152f";
-  };
-  buildInputs = [yacc];
-  propagatedBuildInputs = [m4];
-}