diff --git a/pkgs/os-specific/linux/apparmor/2.9/default.nix b/pkgs/os-specific/linux/apparmor/2.9/default.nix
index 2d7400ad2fad..b1f424fdf1f6 100644
--- a/pkgs/os-specific/linux/apparmor/2.9/default.nix
+++ b/pkgs/os-specific/linux/apparmor/2.9/default.nix
@@ -20,6 +20,12 @@ let
     sha256 = "a63b8724c36c29ed438c9e3ca403bfeeb6c998a45990e300aa1b10faa23a0a22";
   };
 
+  prePatchCommon = ''
+    substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2man" "${perl}/bin/pod2man"
+    substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2html" "${perl}/bin/pod2html"
+    substituteInPlace ./common/Make.rules --replace "/usr/include/linux/capability.h" "${glibc}/include/linux/capability.h"
+  '';
+
   libapparmor = stdenv.mkDerivation {
     name = "libapparmor-${apparmor-version}";
     src = apparmor-sources;
@@ -39,11 +45,7 @@ let
       which
     ];
 
-    prePatch = ''
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2man" "${perl}/bin/pod2man"
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2html" "${perl}/bin/pod2html"
-      substituteInPlace ./common/Make.rules --replace "/usr/include/linux/capability.h" "${glibc}/include/linux/capability.h"
-
+    prePatch = prePatchCommon + ''
       substituteInPlace ./libraries/libapparmor/src/Makefile.am --replace "/usr/include/netinet/in.h" "${glibc}/include/netinet/in.h"
       substituteInPlace ./libraries/libapparmor/src/Makefile.in --replace "/usr/include/netinet/in.h" "${glibc}/include/netinet/in.h"
       '';
@@ -72,11 +74,7 @@ let
       which
     ];
 
-    prePatch = ''
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2man" "${perl}/bin/pod2man"
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2html" "${perl}/bin/pod2html"
-      substituteInPlace ./common/Make.rules --replace "/usr/include/linux/capability.h" "${glibc}/include/linux/capability.h"
-    '';
+    prePatch = prePatchCommon;
 
     buildPhase = ''
       cd ./utils
@@ -101,11 +99,7 @@ let
       which
     ];
 
-    prePatch = ''
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2man" "${perl}/bin/pod2man"
-      substituteInPlace ./common/Make.rules --replace "/usr/bin/pod2html" "${perl}/bin/pod2html"
-      substituteInPlace ./common/Make.rules --replace "/usr/include/linux/capability.h" "${glibc}/include/linux/capability.h"
-
+    prePatch = prePatchCommon + ''
       substituteInPlace ./parser/Makefile --replace "/usr/bin/bison" "${bison}/bin/bison"
       substituteInPlace ./parser/Makefile --replace "/usr/bin/flex" "${flex}/bin/flex"
       substituteInPlace ./parser/Makefile --replace "/usr/include/linux/capability.h" "${glibc}/include/linux/capability.h"