diff --git a/pkgs/build-support/grsecurity/default.nix b/pkgs/build-support/grsecurity/default.nix
index 841effcfca11..fc4d1a26d7a7 100644
--- a/pkgs/build-support/grsecurity/default.nix
+++ b/pkgs/build-support/grsecurity/default.nix
@@ -123,12 +123,14 @@ let
     grsecurityOverrider = args: grkern: {
       # Apparently as of gcc 4.6, gcc-plugin headers (which are needed by PaX plugins)
       # include libgmp headers, so we need these extra tweaks
-      buildInputs = args.buildInputs ++ [ pkgs.gmp ];
+      # As of gcc5 we also need libmpc
+      buildInputs = args.buildInputs ++ [ pkgs.gmp pkgs.libmpc pkgs.mpfr ];
       preConfigure = ''
+        extraIncludes="-I${pkgs.gmp}/include -I${pkgs.libmpc}/include -I${pkgs.mpfr}/include"
         ${args.preConfigure or ""}
-        sed -i 's|-I|-I${pkgs.gmp}/include -I|' scripts/gcc-plugin.sh
-        sed -i 's|HOST_EXTRACFLAGS +=|HOST_EXTRACFLAGS += -I${pkgs.gmp}/include|' tools/gcc/Makefile
-        sed -i 's|HOST_EXTRACXXFLAGS +=|HOST_EXTRACXXFLAGS += -I${pkgs.gmp}/include|' tools/gcc/Makefile
+        sed -i "s|-I|$extraIncludes -I|" scripts/gcc-plugin.sh
+        sed -i "s|HOST_EXTRACFLAGS +=|HOST_EXTRACFLAGS += $extraIncludes|" tools/gcc/Makefile
+        sed -i "s|HOST_EXTRACXXFLAGS +=|HOST_EXTRACXXFLAGS += $extraIncludes|" tools/gcc/Makefile
         rm localversion-grsec
         echo ${localver grkern} > localversion-grsec
       '';