diff --git a/cluster_config.go b/cluster_config.go
index 873d5803..c9268771 100644
--- a/cluster_config.go
+++ b/cluster_config.go
@@ -11,6 +11,8 @@ import (
 	"sync"
 	"time"
 
+	"github.com/kelseyhightower/envconfig"
+
 	"github.com/ipfs/ipfs-cluster/config"
 
 	crypto "github.com/libp2p/go-libp2p-crypto"
@@ -240,8 +242,7 @@ func isReplicationFactorValid(rplMin, rplMax int) error {
 		return errors.New("cluster.replication_factor_max is wrong")
 	}
 
-	if (rplMin == -1 && rplMax != -1) ||
-		(rplMin != -1 && rplMax == -1) {
+	if (rplMin == -1 && rplMax != -1) || (rplMin != -1 && rplMax == -1) {
 		return errors.New("cluster.replication_factor_min and max must be -1 when one of them is")
 	}
 	return nil
@@ -272,6 +273,8 @@ func (cfg *Config) setDefaults() {
 // sets the Config fields from it. Note that it should be JSON
 // as generated by ToJSON().
 func (cfg *Config) LoadJSON(raw []byte) error {
+	cfg.setDefaults()
+
 	jcfg := &configJSON{}
 	err := json.Unmarshal(raw, jcfg)
 	if err != nil {
@@ -279,10 +282,6 @@ func (cfg *Config) LoadJSON(raw []byte) error {
 		return err
 	}
 
-	// Make sure all non-defined keys have good values.
-	cfg.setDefaults()
-	config.SetIfNotDefault(jcfg.PeerstoreFile, &cfg.PeerstoreFile)
-
 	if jcfg.Peers != nil || jcfg.Bootstrap != nil {
 		logger.Error(`
 Your configuration is using cluster.Peers and/or cluster.Bootstrap
@@ -303,6 +302,12 @@ for more information.`)
 		return errors.New("cluster.Peers and cluster.Bootstrap keys have been deprecated")
 	}
 
+	// override json config with env var
+	err = envconfig.Process(cfg.ConfigKey(), jcfg)
+	if err != nil {
+		return err
+	}
+
 	parseDuration := func(txt string) time.Duration {
 		d, _ := time.ParseDuration(txt)
 		if txt != "" && d == 0 {
@@ -311,6 +316,8 @@ for more information.`)
 		return d
 	}
 
+	config.SetIfNotDefault(jcfg.PeerstoreFile, &cfg.PeerstoreFile)
+
 	id, err := peer.IDB58Decode(jcfg.ID)
 	if err != nil {
 		err = fmt.Errorf("error decoding cluster ID: %s", err)
diff --git a/cluster_config_test.go b/cluster_config_test.go
index 004be665..2af5ec0b 100644
--- a/cluster_config_test.go
+++ b/cluster_config_test.go
@@ -2,6 +2,7 @@ package ipfscluster
 
 import (
 	"encoding/json"
+	"os"
 	"testing"
 )
 
@@ -23,118 +24,178 @@ var ccfgTestJSON = []byte(`
 `)
 
 func TestLoadJSON(t *testing.T) {
-	cfg := &Config{}
-	err := cfg.LoadJSON(ccfgTestJSON)
-	if err != nil {
-		t.Fatal(err)
+	loadJSON := func(t *testing.T) (*Config, error) {
+		cfg := &Config{}
+		err := cfg.LoadJSON(ccfgTestJSON)
+		if err != nil {
+			return cfg, err
+		}
+		return cfg, nil
 	}
 
-	if cfg.Peername != "testpeer" {
-		t.Error("expected peername 'testpeer'")
+	t.Run("basic", func(t *testing.T) {
+		cfg := &Config{}
+		err := cfg.LoadJSON(ccfgTestJSON)
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+
+	t.Run("peername", func(t *testing.T) {
+		cfg, err := loadJSON(t)
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.Peername != "testpeer" {
+			t.Error("expected peername 'testpeer'")
+		}
+	})
+
+	t.Run("expected replication factor", func(t *testing.T) {
+		cfg, err := loadJSON(t)
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.ReplicationFactorMin != 5 {
+			t.Error("expected replication factor min == 5")
+		}
+	})
+
+	t.Run("expected disable_repinning", func(t *testing.T) {
+		cfg, err := loadJSON(t)
+		if err != nil {
+			t.Error(err)
+		}
+		if !cfg.DisableRepinning {
+			t.Error("expected disable_repinning to be true")
+		}
+	})
+
+	loadJSON2 := func(t *testing.T, f func(j *configJSON)) (*Config, error) {
+		cfg := &Config{}
+		j := &configJSON{}
+		json.Unmarshal(ccfgTestJSON, j)
+		f(j)
+		tst, err := json.Marshal(j)
+		if err != nil {
+			return cfg, err
+		}
+		err = cfg.LoadJSON(tst)
+		if err != nil {
+			return cfg, err
+		}
+		return cfg, nil
 	}
 
-	if cfg.ReplicationFactorMin != 5 {
-		t.Error("expected replication factor min == 5")
-	}
+	t.Run("bad id", func(t *testing.T) {
+		_, err := loadJSON2(t, func(j *configJSON) { j.ID = "abc" })
+		if err == nil {
+			t.Error("expected error decoding ID")
+		}
+	})
 
-	if !cfg.DisableRepinning {
-		t.Error("expected disable_repinning to be true")
-	}
+	t.Run("empty default peername", func(t *testing.T) {
+		cfg, err := loadJSON2(t, func(j *configJSON) { j.Peername = "" })
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.Peername == "" {
+			t.Error("expected default peername")
+		}
+	})
 
-	j := &configJSON{}
+	t.Run("bad private key", func(t *testing.T) {
+		_, err := loadJSON2(t, func(j *configJSON) { j.PrivateKey = "abc" })
+		if err == nil {
+			t.Error("expected error parsing private key")
+		}
+	})
 
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ID = "abc"
-	tst, _ := json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error decoding ID")
-	}
+	t.Run("bad listen multiaddress", func(t *testing.T) {
+		_, err := loadJSON2(t, func(j *configJSON) { j.ListenMultiaddress = "abc" })
+		if err == nil {
+			t.Error("expected error parsing listen_multiaddress")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.Peername = ""
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if cfg.Peername == "" {
-		t.Error("expected default peername")
-	}
+	t.Run("bad secret", func(t *testing.T) {
+		_, err := loadJSON2(t, func(j *configJSON) { j.Secret = "abc" })
+		if err == nil {
+			t.Error("expected error decoding secret")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.PrivateKey = "abc"
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error parsing private key")
-	}
+	t.Run("default replication factors", func(t *testing.T) {
+		cfg, err := loadJSON2(
+			t,
+			func(j *configJSON) {
+				j.ReplicationFactor = 0
+				j.ReplicationFactorMin = 0
+				j.ReplicationFactorMax = 0
+			},
+		)
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.ReplicationFactorMin != -1 || cfg.ReplicationFactorMax != -1 {
+			t.Error("expected default replication factor")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ListenMultiaddress = "abc"
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error parsing listen_multiaddress")
-	}
+	t.Run("replication factor min/max override", func(t *testing.T) {
+		cfg, err := loadJSON2(t, func(j *configJSON) { j.ReplicationFactor = 3 })
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.ReplicationFactorMin != 3 || cfg.ReplicationFactorMax != 3 {
+			t.Error("expected replicationFactor Min/Max override")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.Secret = "abc"
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error decoding secret")
-	}
+	t.Run("only replication factor min set to -1", func(t *testing.T) {
+		_, err := loadJSON2(t, func(j *configJSON) { j.ReplicationFactorMin = -1 })
+		if err == nil {
+			t.Error("expected error when only one replication factor is -1")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ReplicationFactor = 0
-	j.ReplicationFactorMin = 0
-	j.ReplicationFactorMax = 0
-	tst, _ = json.Marshal(j)
-	cfg.LoadJSON(tst)
-	if cfg.ReplicationFactorMin != -1 || cfg.ReplicationFactorMax != -1 {
-		t.Error("expected default replication factor")
-	}
+	t.Run("replication factor min > max", func(t *testing.T) {
+		_, err := loadJSON2(
+			t,
+			func(j *configJSON) {
+				j.ReplicationFactorMin = 5
+				j.ReplicationFactorMax = 4
+			},
+		)
+		if err == nil {
+			t.Error("expected error when only rplMin > rplMax")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ReplicationFactor = 3
-	tst, _ = json.Marshal(j)
-	cfg.LoadJSON(tst)
-	if cfg.ReplicationFactorMin != 3 || cfg.ReplicationFactorMax != 3 {
-		t.Error("expected replicationFactor Min/Max override")
-	}
+	t.Run("default replication factor", func(t *testing.T) {
+		cfg, err := loadJSON2(
+			t,
+			func(j *configJSON) {
+				j.ReplicationFactorMin = 0
+				j.ReplicationFactorMax = 0
+			},
+		)
+		if err != nil {
+			t.Error(err)
+		}
+		if cfg.ReplicationFactorMin != -1 || cfg.ReplicationFactorMax != -1 {
+			t.Error("expected default replication factors")
+		}
+	})
 
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ReplicationFactorMin = -1
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error when only one replication factor is -1")
-	}
-
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ReplicationFactorMin = 5
-	j.ReplicationFactorMax = 4
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if err == nil {
-		t.Error("expected error when only rplMin > rplMax")
-	}
-
-	j = &configJSON{}
-	json.Unmarshal(ccfgTestJSON, j)
-	j.ReplicationFactorMin = 0
-	j.ReplicationFactorMax = 0
-	tst, _ = json.Marshal(j)
-	err = cfg.LoadJSON(tst)
-	if cfg.ReplicationFactorMin != -1 || cfg.ReplicationFactorMax != -1 {
-		t.Error("expected default replication factors")
-	}
+	t.Run("env var override", func(t *testing.T) {
+		os.Setenv("CLUSTER_PEERNAME", "envsetpeername")
+		cfg := &Config{}
+		cfg.LoadJSON(ccfgTestJSON)
+		if cfg.Peername != "envsetpeername" {
+			t.Fatal("failed to override peername with env var")
+		}
+	})
 }
 
 func TestToJSON(t *testing.T) {
diff --git a/package.json b/package.json
index 366d7a86..3522d994 100644
--- a/package.json
+++ b/package.json
@@ -149,6 +149,12 @@
       "hash": "QmZMWMvWMVKCbHetJ4RgndbuEF1io2UpUxwQwtNjtYPzSC",
       "name": "go-ipfs-files",
       "version": "1.0.1"
+    },
+    {
+      "author": "lanzafame",
+      "hash": "QmVPrFJ6dYJyt7uULgE7wouhvXDzYBZVjYvjMCE5Uqxgfy",
+      "name": "envconfig",
+      "version": "0.0.0"
     }
   ],
   "gxVersion": "0.11.0",