diff --git a/bin/tests/system/dnssec/ns3/secure.example.db.in b/bin/tests/system/dnssec/ns3/secure.example.db.in
index ec39308e9a..883e06790b 100644
--- a/bin/tests/system/dnssec/ns3/secure.example.db.in
+++ b/bin/tests/system/dnssec/ns3/secure.example.db.in
@@ -47,3 +47,8 @@ rrsigonly		A	10.0.0.29
 cnameandkey		CNAME	@
 cnamenokey		CNAME	@
 dnameandkey		DNAME	@
+
+mixedcase		A	10.0.0.30
+mixedCASE		TXT	"mixed case"
+MIXEDcase		AAAA	2002::
+mIxEdCaSe		LOC	37 52 56.788 N 121 54 55.02 W 1120m 10m 100m 10m
diff --git a/bin/tests/system/dnssec/ns3/sign.sh b/bin/tests/system/dnssec/ns3/sign.sh
index 2f3b0de923..14fc709bfb 100644
--- a/bin/tests/system/dnssec/ns3/sign.sh
+++ b/bin/tests/system/dnssec/ns3/sign.sh
@@ -87,7 +87,9 @@ keyname=$("$KEYGEN" -q -a "$DEFAULT_ALGORITHM" -b "$DEFAULT_BITS" -n zone "$zone
 
 cat "$infile" "$cnameandkey.key" "$dnameandkey.key" "$keyname.key" >"$zonefile"
 
-"$SIGNER" -z -o "$zone" "$zonefile" >/dev/null
+"$SIGNER" -z -D -o "$zone" "$zonefile" >/dev/null
+cat "$zonefile" "$zonefile".signed >"$zonefile".tmp
+mv "$zonefile".tmp "$zonefile".signed
 
 zone=bogus.example.
 infile=bogus.example.db.in
diff --git a/bin/tests/system/dnssec/tests.sh b/bin/tests/system/dnssec/tests.sh
index bdaac667e0..02040b914d 100644
--- a/bin/tests/system/dnssec/tests.sh
+++ b/bin/tests/system/dnssec/tests.sh
@@ -766,6 +766,21 @@ n=$((n + 1))
 test "$ret" -eq 0 || echo_i "failed"
 status=$((status + ret))
 
+echo_i "checking mixed-case positive validation ($n)"
+ret=0
+for type in a txt aaaa loc; do
+  dig_with_opts +noauth mixedcase.secure.example. \
+    @10.53.0.3 $type >dig.out.$type.ns3.test$n || ret=1
+  dig_with_opts +noauth mixedcase.secure.example. \
+    @10.53.0.4 $type >dig.out.$type.ns4.test$n || ret=1
+  digcomp --lc dig.out.$type.ns3.test$n dig.out.$type.ns4.test$n || ret=1
+  grep "status: NOERROR" dig.out.$type.ns4.test$n >/dev/null || ret=1
+  grep "flags:.*ad.*QUERY" dig.out.$type.ns4.test$n >/dev/null || ret=1
+done
+n=$((n + 1))
+test "$ret" -eq 0 || echo_i "failed"
+status=$((status + ret))
+
 echo_i "checking multi-stage positive validation NSEC/NSEC3 ($n)"
 ret=0
 dig_with_opts +noauth a.nsec3.example. \