diff --git a/pkgs/os-specific/linux/kernel/common-config.nix b/pkgs/os-specific/linux/kernel/common-config.nix
index d5c754eebc7..f600f49a132 100644
--- a/pkgs/os-specific/linux/kernel/common-config.nix
+++ b/pkgs/os-specific/linux/kernel/common-config.nix
@@ -332,14 +332,20 @@ with stdenv.lib;
   TRANSPARENT_HUGEPAGE_ALWAYS? n
   TRANSPARENT_HUGEPAGE_MADVISE? y
 
-  # zram support (e.g for in-memory compressed swap)
+  # zram support (e.g for in-memory compressed swap).
   ${optionalString (versionAtLeast version "3.4") ''
     ZSMALLOC y
   ''}
   ZRAM m
-  
+
   ${optionalString (versionAtLeast version "3.17") "NFC? n"}
 
+  # Enable firmware loading via udev. Only needed for non-declarative
+  # firmware in /root/test-firmware.
+  ${optionalString (versionAtLeast version "3.17") ''
+    FW_LOADER_USER_HELPER_FALLBACK y
+  ''}
+
   ${kernelPlatform.kernelExtraConfig or ""}
   ${extraConfig}
 ''