diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6566c2d4fe..beec448aef 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -450,6 +450,7 @@ misc:
     - test ! -f CHANGES.SE || sh util/check-line-length.sh CHANGES.SE
     - rm CHANGES.tmp
     - sh util/check-categories.sh
+    - sh util/check-gitignore.sh
     - if git grep SYSTEMTESTTOP -- ':!.gitlab-ci.yml'; then echo 'Please use relative paths instead of $SYSTEMTESTTOP.'; exit 1; fi
     - bash util/unused-headers.sh
     - bash util/xmllint-html.sh
diff --git a/bin/tests/system/rpzrecurse/.gitignore b/bin/tests/system/rpzrecurse/.gitignore
index 3132239b3c..5d4371d852 100644
--- a/bin/tests/system/rpzrecurse/.gitignore
+++ b/bin/tests/system/rpzrecurse/.gitignore
@@ -4,7 +4,6 @@
 /ns3/named.conf
 /ns3/named2.conf
 /ns4/named.conf
-/ans5/ans.pl
 /ans5/ans.pid
 /dnsrps-secondary.conf
 /dnsrps.conf
diff --git a/bin/tests/system/rpzrecurse/ns2/.gitignore b/bin/tests/system/rpzrecurse/ns2/.gitignore
index db4f2c3d45..69f6f6cee2 100644
--- a/bin/tests/system/rpzrecurse/ns2/.gitignore
+++ b/bin/tests/system/rpzrecurse/ns2/.gitignore
@@ -1,3 +1,8 @@
 /*.local
 /*.queries
-/*.conf
+/named.1*.conf
+/named.2*.conf
+/named.3*.conf
+/named.4*.conf
+/named.5*.conf
+/named.6*.conf
diff --git a/bin/tests/system/rrsetorder/dig.out.fixed.good b/bin/tests/system/rrsetorder/reference.dig.out.fixed.good
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.fixed.good
rename to bin/tests/system/rrsetorder/reference.dig.out.fixed.good
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good1 b/bin/tests/system/rrsetorder/reference.dig.out.random.good1
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good1
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good1
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good10 b/bin/tests/system/rrsetorder/reference.dig.out.random.good10
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good10
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good10
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good11 b/bin/tests/system/rrsetorder/reference.dig.out.random.good11
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good11
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good11
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good12 b/bin/tests/system/rrsetorder/reference.dig.out.random.good12
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good12
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good12
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good13 b/bin/tests/system/rrsetorder/reference.dig.out.random.good13
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good13
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good13
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good14 b/bin/tests/system/rrsetorder/reference.dig.out.random.good14
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good14
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good14
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good15 b/bin/tests/system/rrsetorder/reference.dig.out.random.good15
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good15
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good15
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good16 b/bin/tests/system/rrsetorder/reference.dig.out.random.good16
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good16
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good16
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good17 b/bin/tests/system/rrsetorder/reference.dig.out.random.good17
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good17
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good17
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good18 b/bin/tests/system/rrsetorder/reference.dig.out.random.good18
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good18
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good18
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good19 b/bin/tests/system/rrsetorder/reference.dig.out.random.good19
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good19
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good19
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good2 b/bin/tests/system/rrsetorder/reference.dig.out.random.good2
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good2
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good2
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good20 b/bin/tests/system/rrsetorder/reference.dig.out.random.good20
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good20
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good20
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good21 b/bin/tests/system/rrsetorder/reference.dig.out.random.good21
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good21
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good21
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good22 b/bin/tests/system/rrsetorder/reference.dig.out.random.good22
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good22
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good22
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good23 b/bin/tests/system/rrsetorder/reference.dig.out.random.good23
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good23
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good23
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good24 b/bin/tests/system/rrsetorder/reference.dig.out.random.good24
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good24
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good24
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good3 b/bin/tests/system/rrsetorder/reference.dig.out.random.good3
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good3
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good3
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good4 b/bin/tests/system/rrsetorder/reference.dig.out.random.good4
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good4
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good4
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good5 b/bin/tests/system/rrsetorder/reference.dig.out.random.good5
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good5
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good5
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good6 b/bin/tests/system/rrsetorder/reference.dig.out.random.good6
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good6
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good6
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good7 b/bin/tests/system/rrsetorder/reference.dig.out.random.good7
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good7
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good7
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good8 b/bin/tests/system/rrsetorder/reference.dig.out.random.good8
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good8
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good8
diff --git a/bin/tests/system/rrsetorder/dig.out.random.good9 b/bin/tests/system/rrsetorder/reference.dig.out.random.good9
similarity index 100%
rename from bin/tests/system/rrsetorder/dig.out.random.good9
rename to bin/tests/system/rrsetorder/reference.dig.out.random.good9
diff --git a/bin/tests/system/rrsetorder/tests.sh b/bin/tests/system/rrsetorder/tests.sh
index c2d94d8bd6..524efd984f 100644
--- a/bin/tests/system/rrsetorder/tests.sh
+++ b/bin/tests/system/rrsetorder/tests.sh
@@ -41,7 +41,7 @@ if $test_fixed; then
     for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
     do
     dig_cmd @10.53.0.1 fixed.example > dig.out.fixed || ret=1
-    diff dig.out.fixed dig.out.fixed.good >/dev/null || ret=1
+    diff dig.out.fixed reference.dig.out.fixed.good >/dev/null || ret=1
     done
     if [ $ret != 0 ]; then echo_i "failed"; fi
     status=$((status + ret))
@@ -133,7 +133,7 @@ do
     match=0
     for j in $GOOD_RANDOM
     do
-	eval "diff dig.out.random dig.out.random.good$j >/dev/null && match$j=1 match=1"
+	eval "diff dig.out.random reference.dig.out.random.good$j >/dev/null && match$j=1 match=1"
 	if [ $match -eq 1 ]; then break; fi
     done
     if [ $match -eq 0 ]; then ret=1; fi
@@ -172,7 +172,7 @@ if $test_fixed; then
     for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
     do
     dig_cmd @10.53.0.2 fixed.example > dig.out.fixed || ret=1
-    diff dig.out.fixed dig.out.fixed.good || ret=1
+    diff dig.out.fixed reference.dig.out.fixed.good || ret=1
     done
     if [ $ret != 0 ]; then echo_i "failed"; fi
     status=$((status + ret))
@@ -242,7 +242,7 @@ do
     match=0
     for j in $GOOD_RANDOM
     do
-	eval "diff dig.out.random dig.out.random.good$j >/dev/null && match$j=1 match=1"
+	eval "diff dig.out.random reference.dig.out.random.good$j >/dev/null && match$j=1 match=1"
 	if [ $match -eq 1 ]; then break; fi
     done
     if [ $match -eq 0 ]; then ret=1; fi
@@ -297,7 +297,7 @@ if $test_fixed; then
     for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
     do
     dig_cmd @10.53.0.2 fixed.example > dig.out.fixed || ret=1
-    diff dig.out.fixed dig.out.fixed.good || ret=1
+    diff dig.out.fixed reference.dig.out.fixed.good || ret=1
     done
     if [ $ret != 0 ]; then echo_i "failed"; fi
     status=$((status + ret))
@@ -367,7 +367,7 @@ do
     match=0
     for j in $GOOD_RANDOM
     do
-	eval "diff dig.out.random dig.out.random.good$j >/dev/null && match$j=1 match=1"
+	eval "diff dig.out.random reference.dig.out.random.good$j >/dev/null && match$j=1 match=1"
 	if [ $match -eq 1 ]; then break; fi
     done
     if [ $match -eq 0 ]; then ret=1; fi
@@ -406,7 +406,7 @@ if $test_fixed; then
     for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
     do
     dig_cmd @10.53.0.3 fixed.example > dig.out.fixed || ret=1
-    diff dig.out.fixed dig.out.fixed.good || ret=1
+    diff dig.out.fixed reference.dig.out.fixed.good || ret=1
     done
     if [ $ret != 0 ]; then echo_i "failed"; fi
     status=$((status + ret))
@@ -480,7 +480,7 @@ do
     match=0
     for j in $GOOD_RANDOM
     do
-	eval "diff dig.out.random dig.out.random.good$j >/dev/null && match$j=1 match=1"
+	eval "diff dig.out.random reference.dig.out.random.good$j >/dev/null && match$j=1 match=1"
 	if [ $match -eq 1 ]; then break; fi
     done
     if [ $match -eq 0 ]; then ret=1; fi
@@ -522,7 +522,7 @@ do
     match=0
     for j in $GOOD_RANDOM
     do
-	eval "diff dig.out.random dig.out.random.good$j >/dev/null && match$j=1 match=1"
+	eval "diff dig.out.random reference.dig.out.random.good$j >/dev/null && match$j=1 match=1"
 	if [ $match -eq 1 ]; then break; fi
     done
     if [ $match -eq 0 ]; then ret=1; fi
diff --git a/bin/tests/system/serve-stale/.gitignore b/bin/tests/system/serve-stale/.gitignore
index 3d3bc7f474..518f051e4b 100644
--- a/bin/tests/system/serve-stale/.gitignore
+++ b/bin/tests/system/serve-stale/.gitignore
@@ -1,5 +1,4 @@
 /ans2/ans.pid
-/ans2/ans.pl
 /ns1/named.conf
 /ns3/named.conf
 /ns3/root.bk
diff --git a/contrib/dlz/modules/mysqldyn/.gitignore b/contrib/dlz/modules/mysqldyn/.gitignore
deleted file mode 100644
index f3c7a7c5da..0000000000
--- a/contrib/dlz/modules/mysqldyn/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-Makefile
diff --git a/util/check-gitignore.sh b/util/check-gitignore.sh
new file mode 100755
index 0000000000..d273dd464e
--- /dev/null
+++ b/util/check-gitignore.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0.  If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+ignored_yet_tracked="$(git ls-files --cached --ignored --exclude-standard | git check-ignore --verbose --stdin --no-index)"
+
+if [ -n "${ignored_yet_tracked}" ]; then
+	echo "The following .gitignore files contain patterns matching tracked files:"
+	echo
+	echo "${ignored_yet_tracked}"
+	echo
+	echo "Please adjust the contents of the above .gitignore files and/or the names of the tracked files."
+	exit 1
+fi