diff --git a/beacon-chain/blockchain/forkchoice/process_block.go b/beacon-chain/blockchain/forkchoice/process_block.go
index a593dd7993e0..735e0d9b99cc 100644
--- a/beacon-chain/blockchain/forkchoice/process_block.go
+++ b/beacon-chain/blockchain/forkchoice/process_block.go
@@ -486,7 +486,8 @@ func (s *Store) currentSlot() uint64 {
 
 // updates justified check point in store if a better check point is known
 func (s *Store) updateJustifiedCheckpoint() {
-	if helpers.SlotsSinceEpochStarts(s.currentSlot()) == 0 {
+	// Update at epoch boundary slot only
+	if !helpers.IsEpochStart(s.currentSlot()) {
 		return
 	}
 	if s.bestJustifiedCheckpt.Epoch > s.justifiedCheckpt.Epoch {
diff --git a/beacon-chain/blockchain/forkchoice/process_block_test.go b/beacon-chain/blockchain/forkchoice/process_block_test.go
index 9d313fe9e8b4..579d9e3ba42e 100644
--- a/beacon-chain/blockchain/forkchoice/process_block_test.go
+++ b/beacon-chain/blockchain/forkchoice/process_block_test.go
@@ -1,10 +1,12 @@
 package forkchoice
 
 import (
+	"bytes"
 	"context"
 	"reflect"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/go-ssz"
@@ -334,3 +336,115 @@ func TestRemoveStateSinceLastFinalized(t *testing.T) {
 		}
 	}
 }
+
+func TestShouldUpdateJustified_ReturnTrue(t *testing.T) {
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	params.UseMinimalConfig()
+	defer params.UseMainnetConfig()
+
+	store := NewForkChoiceService(ctx, db)
+	store.genesisTime = uint64(time.Now().Unix())
+
+	update, err := store.shouldUpdateJustified(ctx, &ethpb.Checkpoint{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !update {
+		t.Error("Should be able to update justified, received false")
+	}
+
+	lastJustifiedBlk := &ethpb.BeaconBlock{ParentRoot: []byte{'G'}}
+	lastJustifiedRoot, _ := ssz.SigningRoot(lastJustifiedBlk)
+	newJustifiedBlk := &ethpb.BeaconBlock{Slot: 1, ParentRoot: lastJustifiedRoot[:]}
+	newJustifiedRoot, _ := ssz.SigningRoot(newJustifiedBlk)
+	if err := store.db.SaveBlock(ctx, newJustifiedBlk); err != nil {
+		t.Fatal(err)
+	}
+	if err := store.db.SaveBlock(ctx, lastJustifiedBlk); err != nil {
+		t.Fatal(err)
+	}
+
+	diff := (params.BeaconConfig().SlotsPerEpoch - 1) * params.BeaconConfig().SecondsPerSlot
+	store.genesisTime = uint64(time.Now().Unix()) - diff
+	store.justifiedCheckpt = &ethpb.Checkpoint{Root: lastJustifiedRoot[:]}
+	update, err = store.shouldUpdateJustified(ctx, &ethpb.Checkpoint{Root: newJustifiedRoot[:]})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !update {
+		t.Error("Should be able to update justified, received false")
+	}
+}
+
+func TestShouldUpdateJustified_ReturnFalse(t *testing.T) {
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	params.UseMinimalConfig()
+	defer params.UseMainnetConfig()
+
+	store := NewForkChoiceService(ctx, db)
+
+	lastJustifiedBlk := &ethpb.BeaconBlock{ParentRoot: []byte{'G'}}
+	lastJustifiedRoot, _ := ssz.SigningRoot(lastJustifiedBlk)
+	newJustifiedBlk := &ethpb.BeaconBlock{ParentRoot: lastJustifiedRoot[:]}
+	newJustifiedRoot, _ := ssz.SigningRoot(newJustifiedBlk)
+	if err := store.db.SaveBlock(ctx, newJustifiedBlk); err != nil {
+		t.Fatal(err)
+	}
+	if err := store.db.SaveBlock(ctx, lastJustifiedBlk); err != nil {
+		t.Fatal(err)
+	}
+
+	diff := (params.BeaconConfig().SlotsPerEpoch - 1) * params.BeaconConfig().SecondsPerSlot
+	store.genesisTime = uint64(time.Now().Unix()) - diff
+	store.justifiedCheckpt = &ethpb.Checkpoint{Root: lastJustifiedRoot[:]}
+
+	update, err := store.shouldUpdateJustified(ctx, &ethpb.Checkpoint{Root: newJustifiedRoot[:]})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if update {
+		t.Error("Should not be able to update justified, received true")
+	}
+}
+
+func TestUpdateJustifiedCheckpoint_Update(t *testing.T) {
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	params.UseMinimalConfig()
+	defer params.UseMainnetConfig()
+
+	store := NewForkChoiceService(ctx, db)
+	store.genesisTime = uint64(time.Now().Unix())
+
+	store.justifiedCheckpt = &ethpb.Checkpoint{Root: []byte{'A'}}
+	store.bestJustifiedCheckpt = &ethpb.Checkpoint{Epoch: 1, Root: []byte{'B'}}
+	store.updateJustifiedCheckpoint()
+
+	if !bytes.Equal(store.justifiedCheckpt.Root, []byte{'B'}) {
+		t.Error("Justified check point root did not update")
+	}
+}
+
+func TestUpdateJustifiedCheckpoint_NoUpdate(t *testing.T) {
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	params.UseMinimalConfig()
+	defer params.UseMainnetConfig()
+
+	store := NewForkChoiceService(ctx, db)
+	store.genesisTime = uint64(time.Now().Unix()) - params.BeaconConfig().SecondsPerSlot
+
+	store.justifiedCheckpt = &ethpb.Checkpoint{Root: []byte{'A'}}
+	store.bestJustifiedCheckpt = &ethpb.Checkpoint{Epoch: 1, Root: []byte{'B'}}
+	store.updateJustifiedCheckpoint()
+
+	if bytes.Equal(store.justifiedCheckpt.Root, []byte{'B'}) {
+		t.Error("Justified check point root was not suppose to update")
+	}
+}
diff --git a/beacon-chain/core/helpers/slot_epoch_test.go b/beacon-chain/core/helpers/slot_epoch_test.go
index 2a1bdc853bf5..017360592c2d 100644
--- a/beacon-chain/core/helpers/slot_epoch_test.go
+++ b/beacon-chain/core/helpers/slot_epoch_test.go
@@ -156,3 +156,21 @@ func TestIsEpochEnd(t *testing.T) {
 		}
 	}
 }
+
+func TestSlotsSinceEpochStarts(t *testing.T) {
+	tests := []struct {
+		slots       uint64
+		wantedSlots uint64
+	}{
+		{slots: 0, wantedSlots: 0},
+		{slots: 1, wantedSlots: 1},
+		{slots: params.BeaconConfig().SlotsPerEpoch - 1, wantedSlots: params.BeaconConfig().SlotsPerEpoch - 1},
+		{slots: params.BeaconConfig().SlotsPerEpoch + 1, wantedSlots: 1},
+		{slots: 10*params.BeaconConfig().SlotsPerEpoch + 2, wantedSlots: 2},
+	}
+	for _, tt := range tests {
+		if got := SlotsSinceEpochStarts(tt.slots); got != tt.wantedSlots {
+			t.Errorf("SlotsSinceEpochStarts() = %v, want %v", got, tt.wantedSlots)
+		}
+	}
+}