diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0a062c1..6aa921e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,14 +1,20 @@
 EXTRA_DIST = \
 	bootp \
+	full-json \
 	confs \
 	expected \
 	leading0 \
 	leases \
-	simple \
-	test.sh
+	same-twice \
+	simple
 
-TESTS = simple bootp leading0 v6
-check_SCRIPTS = test.sh
+TESTS = \
+	bootp \
+	full-json \
+	leading0 \
+	same-twice \
+	simple \
+	v6
 
 check-local: $(SHELL) $(top_srcdir)/tests/test.sh
 
diff --git a/tests/confs/same-twice b/tests/confs/same-twice
new file mode 120000
index 0000000..8fd3246
--- /dev/null
+++ b/tests/confs/same-twice
@@ -0,0 +1 @@
+simple
\ No newline at end of file
diff --git a/tests/expected/same-twice b/tests/expected/same-twice
new file mode 100644
index 0000000..477fc7e
--- /dev/null
+++ b/tests/expected/same-twice
@@ -0,0 +1,10 @@
+Ranges:
+shared net name     first ip           last ip            max   cur    percent  touch   t+c  t+c perc
+All networks        10.0.0.1         - 10.0.0.10           10     1     10.000      0     1    10.000
+
+Shared networks:
+name                   max   cur     percent  touch    t+c  t+c perc
+
+Sum of all ranges:
+name                   max   cur     percent  touch    t+c  t+c perc
+All networks            10     1     10.000       0      1    10.000
diff --git a/tests/expected/same-twice-json b/tests/expected/same-twice-json
new file mode 100644
index 0000000..aa0c419
--- /dev/null
+++ b/tests/expected/same-twice-json
@@ -0,0 +1,16 @@
+{
+   "active_leases": [
+         { "ip":"10.0.0.5", "macaddress":"00:00:00:00:00:00" }
+   ],
+   "subnets": [
+         { "location":"All networks", "range":"10.0.0.1 - 10.0.0.10", "defined":10, "used":1, "free":9 }
+   ],
+   "shared-networks": [
+   ],
+   "summary": {
+         "location":"All networks",
+         "defined":10,
+         "used":1,
+         "free":9
+   }
+}
diff --git a/tests/full-json b/tests/full-json
new file mode 100755
index 0000000..93c4ffd
--- /dev/null
+++ b/tests/full-json
@@ -0,0 +1,14 @@
+#!/bin/sh
+#
+# Minimal regression test suite.
+
+TEST_TOPDIR=$(cd $(dirname $0) && pwd)
+DHCPD_POOLS=$(readlink -f $TEST_TOPDIR/../src/dhcpd-pools)
+
+if [ ! -d outputs ]; then
+	mkdir outputs
+fi
+
+$DHCPD_POOLS -f J -c confs/same-twice -l leases/same-twice -o outputs/same-twice-json
+diff -u expected/same-twice-json outputs/same-twice-json
+exit $?
diff --git a/tests/leases/same-twice b/tests/leases/same-twice
new file mode 100644
index 0000000..1a5179a
--- /dev/null
+++ b/tests/leases/same-twice
@@ -0,0 +1,10 @@
+lease 10.0.0.5 {
+  binding state active;
+  next binding state free;
+  hardware ethernet be:ef:00:00:co:de;
+}
+lease 10.0.0.5 {
+  binding state active;
+  next binding state free;
+  hardware ethernet 00:00:00:00:00:00;
+}
diff --git a/tests/same-twice b/tests/same-twice
new file mode 120000
index 0000000..61a58b0
--- /dev/null
+++ b/tests/same-twice
@@ -0,0 +1 @@
+test.sh
\ No newline at end of file
diff --git a/tests/test.sh b/tests/test.sh
index f1f1587..3b06828 100755
--- a/tests/test.sh
+++ b/tests/test.sh
@@ -11,5 +11,5 @@ if [ ! -d outputs ]; then
 fi
 
 $DHCPD_POOLS -c confs/$IAM -l leases/$IAM -o outputs/$IAM
-diff -q expected/$IAM outputs/$IAM >/dev/null
+diff -u expected/$IAM outputs/$IAM
 exit $?