diff --git a/nixos/modules/system/boot/loader/grub/install-grub.pl b/nixos/modules/system/boot/loader/grub/install-grub.pl
index 74eb32d1fc13..c9a51288747b 100644
--- a/nixos/modules/system/boot/loader/grub/install-grub.pl
+++ b/nixos/modules/system/boot/loader/grub/install-grub.pl
@@ -430,7 +430,7 @@ my $tmpFile = $confFile . ".tmp";
 writeFile($tmpFile, $conf);
 
 # Append entries detected by os-prober
-if (get("useOsprober") eq "true") {
+if (get("useOSProber") eq "true") {
     system(get("shell"), "-c", "pkgdatadir=$grub/share/grub $grub/etc/grub.d/30_os-prober >> $tmpFile");
 }