diff --git a/THANKS b/THANKS
index 6e76373..a1ba2bc 100644
--- a/THANKS
+++ b/THANKS
@@ -45,3 +45,4 @@ Boris Lytochkin
 Jeff Bailey
 José Bollo
 Sebastián Cramatte
+Mark Sangster
diff --git a/src/output.c b/src/output.c
index a2f0c29..275e431 100644
--- a/src/output.c
+++ b/src/output.c
@@ -158,11 +158,11 @@ int shnet_output_helper(struct conf_t *state, struct output_helper_t *oh,
 		oh->status = STATUS_IGNORED;
 		if (state->skip_minsize)
 			return 1;
-	} else if (state->critical < oh->percent && shared_p->used < state->crit_count) {
+	} else if (state->critical < oh->percent && (shared_p->available - shared_p->used) < state->crit_count) {
 		oh->status = STATUS_CRIT;
 		if (state->skip_critical)
 			return 1;
-	} else if (state->warning < oh->percent && shared_p->used < state->warn_count) {
+	} else if (state->warning < oh->percent && (shared_p->available - shared_p->used) < state->warn_count) {
 		oh->status = STATUS_WARN;
 		if (state->skip_warning)
 			return 1;
diff --git a/tests/alarm-count-option b/tests/alarm-count-option
index 763af1b..37d894d 100755
--- a/tests/alarm-count-option
+++ b/tests/alarm-count-option
@@ -32,6 +32,13 @@ dhcpd-pools -c $top_srcdir/tests/confs/complete -l $top_srcdir/tests/leases/comp
 echo $? >> tests/outputs/$IAM-too
 cat tests/outputs/$IAM-too >> tests/outputs/$IAM
 
+echo '== shared net count alarms ==' >> tests/outputs/$IAM
+dhcpd-pools -c $top_srcdir/tests/confs/complete -l $top_srcdir/tests/leases/complete \
+	--color=always --format t --crit-count=20 --critical=0 --warning=0 --warn-count=24 \
+	--output=tests/outputs/$IAM-too
+echo $? >> tests/outputs/$IAM-too
+cat tests/outputs/$IAM-too >> tests/outputs/$IAM
+
 rm -f tests/outputs/$IAM-too
 diff -u $top_srcdir/tests/expected/$IAM tests/outputs/$IAM
 exit $?
diff --git a/tests/expected/alarm-count-option b/tests/expected/alarm-count-option
index 3e9b76d..c2f466e 100644
--- a/tests/expected/alarm-count-option
+++ b/tests/expected/alarm-count-option
@@ -14,3 +14,21 @@ Shared nets - crit: 0 warn: 0 ok: 0 ignored: 2; | snet_crit=0 snet_warn=0 snet_o
 WARNING: dhcpd-pools: Ranges - crit: 0 warn: 0 ok: 2; | range_crit=0 range_warn=0 range_ok=2
 Shared nets - crit: 0 warn: 2 ok: 0; | snet_crit=0 snet_warn=2 snet_ok=0
 1
+== shared net count alarms ==
+Ranges:
+shared net name     first ip           last ip            max   cur    percent  touch   t+c  t+c perc
+example1            10.0.0.1         - 10.0.0.20           20    11     55.000      0    11    55.000
+example1            10.1.0.1         - 10.1.0.20           20    10     50.000      0    10    50.000
+example2            10.2.0.1         - 10.2.0.20           20     8     40.000      0     8    40.000
+example2            10.3.0.1         - 10.3.0.20           20     9     45.000      0     9    45.000
+All networks        10.4.0.1         - 10.4.0.20           20     5     25.000      0     5    25.000
+
+Shared networks:
+name                   max   cur     percent  touch    t+c  t+c perc
+example1                40    21     52.500       0     21    52.500
+example2                40    17     42.500       0     17    42.500
+
+Sum of all ranges:
+name                   max   cur     percent  touch    t+c  t+c perc
+All networks           100    43     43.000       0     43    43.000
+0