diff --git a/netmap/aggregator.go b/netmap/aggregator.go
index c018e6b1..3365fe31 100644
--- a/netmap/aggregator.go
+++ b/netmap/aggregator.go
@@ -23,7 +23,7 @@ type (
 	}
 
 	minAgg struct {
-		min float64
+		min *float64
 	}
 
 	meanIQRAgg struct {
@@ -102,13 +102,17 @@ func (a *meanAgg) Compute() float64 {
 }
 
 func (a *minAgg) Add(n float64) {
-	if a.min == 0 || n < a.min {
-		a.min = n
+	if a.min == nil || n < *a.min {
+		a.min = &n
 	}
 }
 
 func (a *minAgg) Compute() float64 {
-	return a.min
+	if a.min == nil {
+		return 0
+	}
+
+	return *a.min
 }
 
 func (a *meanIQRAgg) Add(n float64) {
diff --git a/netmap/aggregator_test.go b/netmap/aggregator_test.go
new file mode 100644
index 00000000..20ff4d87
--- /dev/null
+++ b/netmap/aggregator_test.go
@@ -0,0 +1,69 @@
+package netmap
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMeanAgg(t *testing.T) {
+	tt := []struct {
+		vals []float64
+		res  float64
+	}{
+		{
+			vals: []float64{0, 1, 3, 4, 5},
+			res:  2.6,
+		},
+		{
+			vals: []float64{0, 0, 0, 0},
+			res:  0,
+		},
+		{
+			vals: []float64{1, 1, 1, 1},
+			res:  1,
+		},
+	}
+
+	for _, test := range tt {
+		a := newMeanAgg()
+		for _, val := range test.vals {
+			a.Add(val)
+		}
+
+		require.Equal(t, test.res, a.Compute())
+	}
+}
+
+func TestMinAgg(t *testing.T) {
+	tt := []struct {
+		vals []float64
+		res  float64
+	}{
+		{
+			vals: []float64{1, 2, 3, 4, 0, 100},
+			res:  0,
+		},
+		{
+			vals: []float64{0, 1, 3, 4, 5},
+			res:  0,
+		},
+		{
+			vals: []float64{0, 0, 0, 0},
+			res:  0,
+		},
+		{
+			vals: []float64{1, 1, 1, 1},
+			res:  1,
+		},
+	}
+
+	for _, test := range tt {
+		a := newMinAgg()
+		for _, val := range test.vals {
+			a.Add(val)
+		}
+
+		require.Equal(t, test.res, a.Compute())
+	}
+}
diff --git a/netmap/json_tests/hrw_sort.json b/netmap/json_tests/hrw_sort.json
index 521a852e..31283566 100644
--- a/netmap/json_tests/hrw_sort.json
+++ b/netmap/json_tests/hrw_sort.json
@@ -2,6 +2,7 @@
   "name": "HRW ordering",
   "nodes": [
     {
+      "public_key": "AsGTU2KO25PRUWal5HzInv3LLqBedankF/scMr7VpVR/",
       "attributes": [
         {
           "key": "Country",
@@ -18,6 +19,7 @@
       ]
     },
     {
+      "public_key": "AltaQMNJ8k3awpg9q8Z+CFMXHt+io4ChddgBuRw8QSN+",
       "attributes": [
         {
           "key": "Country",
@@ -34,6 +36,7 @@
       ]
     },
     {
+      "public_key": "AoV8bh005WYoMAGpucDOZ1O704ySFlypTWP+pJP1trBo",
       "attributes": [
         {
           "key": "Country",
@@ -50,6 +53,7 @@
       ]
     },
     {
+      "public_key": "ApQN0UPXMeBcCiiw+UA3XRe5EESOFbu545lEaThaZ+4L",
       "attributes": [
         {
           "key": "Country",
@@ -66,6 +70,7 @@
       ]
     },
     {
+      "public_key": "AzG1GtS58K92j6dDrGXTzu3EKJ+9GFLZLMK6lpH+mIzE",
       "attributes": [
         {
           "key": "Country",
@@ -82,6 +87,7 @@
       ]
     },
     {
+      "public_key": "AzCRU8cw/WQRPZV/f5PjxXXFSZ7dakRvzlwwEVFQdaz4",
       "attributes": [
         {
           "key": "Country",
@@ -94,6 +100,7 @@
       ]
     },
     {
+      "public_key": "As8NhDYv70g2ivJ95guRdxtDuqzONOv0nlU36xuXI2Mx",
       "attributes": [
         {
           "key": "Country",
@@ -110,6 +117,7 @@
       ]
     },
     {
+      "public_key": "Ax9daczuWTOYdrsmGrqWRkDonY86GD1OE1WUrnsOjE9e",
       "attributes": [
         {
           "key": "Country",
@@ -126,6 +134,7 @@
       ]
     },
     {
+      "public_key": "AorNy+ku9CwiGdQO/TjcGHXYmvGks6ZIS9JqVO1+KXze",
       "attributes": [
         {
           "key": "Country",
@@ -146,19 +155,19 @@
     "select 3 nodes in 3 distinct countries, same placement": {
       "policy": {"replicas":[{"count":1,"selector":"Main"}],"containerBackupFactor":1,"selectors":[{"name":"Main","count":3,"clause":"DISTINCT","attribute":"Country","filter":"*"}],"filters":[],"subnetId":null},
       "pivot": "Y29udGFpbmVySUQ=",
-      "result": [[4, 0, 7]],
+      "result": [[1, 7, 5]],
       "placement": {
         "pivot": "b2JqZWN0SUQ=",
-        "result": [[4, 0, 7]]
+        "result": [[1, 7, 5]]
       }
     },
     "select 6 nodes in 3 distinct countries, different placement": {
       "policy": {"replicas":[{"count":1,"selector":"Main"}],"containerBackupFactor":2,"selectors":[{"name":"Main","count":3,"clause":"DISTINCT","attribute":"Country","filter":"*"}],"filters":[],"subnetId":null},
       "pivot": "Y29udGFpbmVySUQ=",
-      "result": [[4, 3, 0, 1, 7, 2]],
+      "result": [[1, 6, 0, 7, 5, 3]],
       "placement": {
         "pivot": "b2JqZWN0SUQ=",
-        "result": [[4, 3, 0, 7, 2, 1]]
+        "result": [[1, 6, 0, 7, 5, 3]]
       }
     }
   }