diff --git a/CHANGES b/CHANGES
index 7afb9bbf67..2d2b85e6a2 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4912.	[test]		Improved the reliability of the 'cds' system test.
+			[GL #136]
+
 4911.	[test]		Improved the reliability of the 'mkeys' system test.
 			[GL #128]
 
diff --git a/bin/tests/system/cds/checkmtime.pl b/bin/tests/system/cds/checkmtime.pl
index aba2105c03..a65938c432 100644
--- a/bin/tests/system/cds/checkmtime.pl
+++ b/bin/tests/system/cds/checkmtime.pl
@@ -13,4 +13,4 @@ my $target = shift;
 my $file = shift;
 my $mtime = time - (stat $file)[9];
 die "bad mtime $mtime"
-	unless abs($mtime - $target) < 10;
+	unless ($mtime - $target >= 0 && $mtime - $target < 60);