diff -Nur a/grub-core/lib/libgcrypt/src/libgcrypt-config.in b/grub-core/lib/libgcrypt/src/libgcrypt-config.in
--- a/grub-core/lib/libgcrypt/src/libgcrypt-config.in	2018-11-24 17:13:02.000000000 +0000
+++ b/grub-core/lib/libgcrypt/src/libgcrypt-config.in	2022-10-05 01:59:10.786495758 +0100
@@ -142,7 +142,7 @@
 
     tmp=""
     for i in $includes $cflags_final; do
-       if echo "$tmp" | fgrep -v -- "$i" >/dev/null; then
+       if echo "$tmp" | grep -Fv -- "$i" >/dev/null; then
            tmp="$tmp $i"
        fi
     done
@@ -163,7 +163,7 @@
 
     tmp=""
     for i in $libdirs $libs_final; do
-       if echo "$tmp" | fgrep -v -- "$i" >/dev/null; then
+       if echo "$tmp" | grep -Fv -- "$i" >/dev/null; then
            tmp="$tmp $i"
        fi
     done
diff -Nur a/util/grub.d/10_hurd.in b/util/grub.d/10_hurd.in
--- a/util/grub.d/10_hurd.in	2018-11-24 17:13:02.000000000 +0000
+++ b/util/grub.d/10_hurd.in	2022-10-05 02:02:09.500500296 +0100
@@ -168,7 +168,7 @@
   hurd_entry "$kernel" advanced
   hurd_entry "$kernel" recovery
 
-  kernels=`echo $kernels | tr ' ' '\n' | fgrep -vx "$kernel" | tr '\n' ' '`
+  kernels=`echo $kernels | tr ' ' '\n' | grep -Fvx "$kernel" | tr '\n' ' '`
 done
 
 # If at least one kernel was found, then we need to
diff -Nur a/util/grub.d/10_kfreebsd.in b/util/grub.d/10_kfreebsd.in
--- a/util/grub.d/10_kfreebsd.in	2018-11-24 17:13:02.000000000 +0000
+++ b/util/grub.d/10_kfreebsd.in	2022-10-05 02:02:31.978500866 +0100
@@ -231,7 +231,7 @@
     kfreebsd_entry "${OS}" "${version}" recovery "-s"
   fi
 
-  list=`echo $list | tr ' ' '\n' | fgrep -vx "$kfreebsd" | tr '\n' ' '`
+  list=`echo $list | tr ' ' '\n' | grep -Fvx "$kfreebsd" | tr '\n' ' '`
 done
 
 # If at least one kernel was found, then we need to
diff -Nur a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
--- a/util/grub.d/10_linux.in	2018-11-24 17:13:02.000000000 +0000
+++ b/util/grub.d/10_linux.in	2022-10-05 02:01:43.687499640 +0100
@@ -282,7 +282,7 @@
                 "single ${GRUB_CMDLINE_LINUX}"
   fi
 
-  list=`echo $list | tr ' ' '\n' | fgrep -vx "$linux" | tr '\n' ' '`
+  list=`echo $list | tr ' ' '\n' | grep -Fvx "$linux" | tr '\n' ' '`
 done
 
 # If at least one kernel was found, then we need to
diff -Nur a/util/grub.d/20_linux_xen.in b/util/grub.d/20_linux_xen.in
--- a/util/grub.d/20_linux_xen.in	2019-04-23 09:54:47.000000000 +0100
+++ b/util/grub.d/20_linux_xen.in	2022-10-05 02:00:13.501497350 +0100
@@ -310,12 +310,12 @@
 		"single ${GRUB_CMDLINE_LINUX}" "${GRUB_CMDLINE_XEN}"
 	fi
 
-	list=`echo $list | tr ' ' '\n' | fgrep -vx "$linux" | tr '\n' ' '`
+	list=`echo $list | tr ' ' '\n' | grep -Fvx "$linux" | tr '\n' ' '`
     done
     if [ x"$is_top_level" != xtrue ]; then
 	echo '	}'
     fi
-    xen_list=`echo $xen_list | tr ' ' '\n' | fgrep -vx "$current_xen" | tr '\n' ' '`
+    xen_list=`echo $xen_list | tr ' ' '\n' | grep -Fvx "$current_xen" | tr '\n' ' '`
 done
 
 # If at least one kernel was found, then we need to