diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b27e4ff..e658e65 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -35,6 +35,8 @@
 my $root;
 my %debug;
 my $help = 0;
+my $acpi_testexpected;
+my $acpi_nontestexpected;
 
 sub help {
 	my ($exitcode) = @_;
@@ -1256,6 +1258,27 @@
 	}
 }
 
+# According to tests/qtest/bios-tables-test.c: do not
+# change expected file in the same commit with adding test
+sub checkfilename {
+	my ($name) = @_;
+	if ($name =~ m#^tests/data/acpi/# and
+		# make exception for a shell script that rebuilds the files
+		not $name =~ m#^\.sh$# or
+		$name =~ m#^tests/qtest/bios-tables-test-allowed-diff.h$#) {
+		$acpi_testexpected = $name;
+	} else {
+		$acpi_nontestexpected = $name;
+	}
+	if (defined $acpi_testexpected and defined $acpi_nontestexpected) {
+		ERROR("Do not add expected files together with tests, " .
+		      "follow instructions in " .
+		      "tests/qtest/bios-tables-test.c: both " .
+		      $acpi_testexpected . " and " .
+		      $acpi_nontestexpected . " found\n");
+	}
+}
+
 sub process {
 	my $filename = shift;
 
@@ -1431,9 +1454,11 @@
 		if ($line =~ /^diff --git.*?(\S+)$/) {
 			$realfile = $1;
 			$realfile =~ s@^([^/]*)/@@ if (!$file);
+	                checkfilename($realfile);
 		} elsif ($line =~ /^\+\+\+\s+(\S+)/) {
 			$realfile = $1;
 			$realfile =~ s@^([^/]*)/@@ if (!$file);
+	                checkfilename($realfile);
 
 			$p1_prefix = $1;
 			if (!$file && $tree && $p1_prefix ne '' &&