diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index 9c30f1fd70d0..5544409a74d6 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -207,6 +207,10 @@ let
         for i in $(find arch -name install.sh); do
             patchShebangs "$i"
         done
+
+        # unset $src because the build system tries to use it and spams a bunch of warnings
+        # see: https://github.com/torvalds/linux/commit/b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0
+        unset src
       '';
 
       configurePhase = ''