diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index bd9334b8f9b7..ebbc69dec593 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -155,14 +155,13 @@ let
                           if platform.kernelTarget == "zImage" || platform.kernelTarget == "Image.gz" then "zinstall" else
                           "install") ];
 
-      postInstall = ''
-        mkdir -p $dev
-        cp vmlinux $dev/
-      '' + (optionalString installsFirmware ''
+      postInstall = (optionalString installsFirmware ''
         mkdir -p $out/lib/firmware
       '') + (if (platform ? kernelDTB && platform.kernelDTB) then ''
         make $makeFlags "''${makeFlagsArray[@]}" dtbs dtbs_install INSTALL_DTBS_PATH=$out/dtbs
       '' else "") + (if isModular then ''
+        mkdir -p $dev
+        cp vmlinux $dev/
         if [ -z "$dontStrip" ]; then
           installFlagsArray+=("INSTALL_MOD_STRIP=1")
         fi
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index ce18e9d3762d..78444eb34d1e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -13331,7 +13331,7 @@ with pkgs;
   linux_samus_latest = linuxPackages_samus_latest.kernel;
 
   # A function to build a manually-configured kernel
-  linuxManualConfig = pkgs.buildLinux;
+  linuxManualConfig = makeOverridable (callPackage ../os-specific/linux/kernel/manual-config.nix {});
   buildLinux = makeOverridable (callPackage ../os-specific/linux/kernel/generic.nix {});
 
   keyutils = callPackage ../os-specific/linux/keyutils { };