diff --git a/pkgs/os-specific/linux/kernel/builder.sh b/pkgs/os-specific/linux/kernel/builder.sh
index 5bedebc11ec..61cb8f28081 100644
--- a/pkgs/os-specific/linux/kernel/builder.sh
+++ b/pkgs/os-specific/linux/kernel/builder.sh
@@ -16,8 +16,8 @@ postPatch() {
 }
 
 configurePhase() {
-    if test -n "$preConfigure"; then 
-        eval "$preConfigure"; 
+    if test -n "$preConfigure"; then
+        eval "$preConfigure";
     fi
 
     export INSTALL_PATH=$out
@@ -46,13 +46,6 @@ configurePhase() {
 }
 
 
-postBuild() {
-    # After the builder did a 'make all' (kernel + modules)
-    # we force building the target asked: bzImage/zImage/uImage/...
-    make $makeFlags $kernelTarget
-    make $makeFlags -C scripts unifdef
-}
-
 installPhase() {
 
     ensureDir $out
@@ -149,8 +142,8 @@ installPhase() {
         fi
     fi
 
-    if test -n "$postInstall"; then 
-        eval "$postInstall"; 
+    if test -n "$postInstall"; then
+        eval "$postInstall";
     fi
 }
 
diff --git a/pkgs/os-specific/linux/kernel/generic.nix b/pkgs/os-specific/linux/kernel/generic.nix
index 42cefd5b584..138c9a53d04 100644
--- a/pkgs/os-specific/linux/kernel/generic.nix
+++ b/pkgs/os-specific/linux/kernel/generic.nix
@@ -35,6 +35,10 @@
 , extraMeta ? {}
 , ubootChooser ? null
 , postInstall ? ""
+
+, # After the builder did a 'make all' (kernel + modules)
+  # we force building the target asked: bzImage/zImage/uImage/...
+  postBuild ? "make $makeFlags $kernelTarget; make $makeFlags -C scripts unifdef"
 , ...
 }: