diff --git a/packages/eventindexer/http/get_stats_test.go b/packages/eventindexer/http/get_stats_test.go
index 08161dedd2..a4c5c6000f 100644
--- a/packages/eventindexer/http/get_stats_test.go
+++ b/packages/eventindexer/http/get_stats_test.go
@@ -2,6 +2,7 @@ package http
 
 import (
 	"context"
+	"math/big"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -15,13 +16,13 @@ import (
 func Test_GetStats(t *testing.T) {
 	srv := newTestServer("")
 
-	var proofTime uint64 = 5
+	var proofTime = big.NewInt(5)
 
-	var proofReward uint64 = 7
+	var proofReward = big.NewInt(7)
 
 	_, err := srv.statRepo.Save(context.Background(), eventindexer.SaveStatOpts{
-		ProofTime:   &proofTime,
-		ProofReward: &proofReward,
+		ProofTime:   proofTime,
+		ProofReward: proofReward,
 	})
 
 	assert.Equal(t, nil, err)
@@ -36,7 +37,7 @@ func Test_GetStats(t *testing.T) {
 			"success",
 			"0x123",
 			http.StatusOK,
-			[]string{`{"id":1,"averageProofTime":5,"averageProofReward":7,"numProofs":1,"numVerifiedBlocks":1}`},
+			[]string{`{"id":1,"averageProofTime":"5","averageProofReward":"7","numProofs":1,"numVerifiedBlocks":1}`},
 		},
 	}
 
diff --git a/packages/eventindexer/indexer/save_block_proven_event.go b/packages/eventindexer/indexer/save_block_proven_event.go
index 2c7eab4c0d..ecc1167c4c 100644
--- a/packages/eventindexer/indexer/save_block_proven_event.go
+++ b/packages/eventindexer/indexer/save_block_proven_event.go
@@ -104,10 +104,19 @@ func (svc *Service) updateAverageProofTime(ctx context.Context, event *taikol1.T
 
 	proofTime := provenAt - proposedAt
 
-	newAverageProofTime := calcNewAverage(stat.AverageProofTime, stat.NumProofs, proofTime)
+	avg, ok := new(big.Int).SetString(stat.AverageProofTime, 10)
+	if !ok {
+		return errors.New("unable to convert average proof time to string")
+	}
+
+	newAverageProofTime := calcNewAverage(
+		avg,
+		new(big.Int).SetUint64(stat.NumProofs),
+		new(big.Int).SetUint64(proofTime),
+	)
 
 	_, err = svc.statRepo.Save(ctx, eventindexer.SaveStatOpts{
-		ProofTime: &newAverageProofTime,
+		ProofTime: newAverageProofTime,
 	})
 	if err != nil {
 		return errors.Wrap(err, "svc.statRepo.Save")
@@ -116,6 +125,9 @@ func (svc *Service) updateAverageProofTime(ctx context.Context, event *taikol1.T
 	return nil
 }
 
-func calcNewAverage(a, t, new uint64) uint64 {
-	return ((a * t) + new) / (t + 1)
+func calcNewAverage(a, t, n *big.Int) *big.Int {
+	m := new(big.Int).Mul(a, t)
+	added := new(big.Int).Add(m, n)
+
+	return new(big.Int).Div(added, t.Add(t, big.NewInt(1)))
 }
diff --git a/packages/eventindexer/indexer/save_block_verified_event.go b/packages/eventindexer/indexer/save_block_verified_event.go
index 6ee3fe9244..e242b1ee54 100644
--- a/packages/eventindexer/indexer/save_block_verified_event.go
+++ b/packages/eventindexer/indexer/save_block_verified_event.go
@@ -80,10 +80,19 @@ func (svc *Service) updateAverageBlockReward(ctx context.Context, event *taikol1
 		return errors.Wrap(err, "svc.statRepo.Find")
 	}
 
-	newAverageProofReward := calcNewAverage(stat.AverageProofReward, stat.NumVerifiedBlocks, reward)
+	avg, ok := new(big.Int).SetString(stat.AverageProofReward, 10)
+	if !ok {
+		return errors.New("unable to convert average proof reward to string")
+	}
+
+	newAverageProofReward := calcNewAverage(
+		avg,
+		new(big.Int).SetUint64(stat.NumVerifiedBlocks),
+		new(big.Int).SetUint64(reward),
+	)
 
 	_, err = svc.statRepo.Save(ctx, eventindexer.SaveStatOpts{
-		ProofReward: &newAverageProofReward,
+		ProofReward: newAverageProofReward,
 	})
 	if err != nil {
 		return errors.Wrap(err, "svc.statRepo.Save")
diff --git a/packages/eventindexer/migrations/1666650701_create_stats_table.sql b/packages/eventindexer/migrations/1666650701_create_stats_table.sql
index 3d3c9c5f44..9a8ea8a6e9 100644
--- a/packages/eventindexer/migrations/1666650701_create_stats_table.sql
+++ b/packages/eventindexer/migrations/1666650701_create_stats_table.sql
@@ -2,8 +2,8 @@
 -- +goose StatementBegin
 CREATE TABLE IF NOT EXISTS stats (
     id int NOT NULL PRIMARY KEY AUTO_INCREMENT,
-    average_proof_time int NOT NULL DEFAULT 0,
-    average_proof_reward int NOT NULL DEFAULT 0,
+    average_proof_time VARCHAR(255) NOT NULL DEFAULT "0",
+    average_proof_reward VARCHAR(255) NOT NULL DEFAULT "0",
     num_proofs int NOT NULL default 0,
     num_verified_blocks int NOT NULL default 0,
     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ,
diff --git a/packages/eventindexer/mock/stat_repository.go b/packages/eventindexer/mock/stat_repository.go
index 4645af5652..f49d29b01f 100644
--- a/packages/eventindexer/mock/stat_repository.go
+++ b/packages/eventindexer/mock/stat_repository.go
@@ -14,10 +14,20 @@ func NewStatRepository() *StatRepository {
 	return &StatRepository{}
 }
 func (r *StatRepository) Save(ctx context.Context, opts eventindexer.SaveStatOpts) (*eventindexer.Stat, error) {
+	proofReward := ""
+	if opts.ProofReward != nil {
+		proofReward = opts.ProofReward.String()
+	}
+
+	proofTime := ""
+	if opts.ProofTime != nil {
+		proofTime = opts.ProofTime.String()
+	}
+
 	r.stats = &eventindexer.Stat{
 		ID:                 1,
-		AverageProofTime:   *opts.ProofTime,
-		AverageProofReward: *opts.ProofReward,
+		AverageProofTime:   proofTime,
+		AverageProofReward: proofReward,
 		NumProofs:          1,
 		NumVerifiedBlocks:  1,
 	}
diff --git a/packages/eventindexer/repo/stat.go b/packages/eventindexer/repo/stat.go
index 711091bd03..65174abb91 100644
--- a/packages/eventindexer/repo/stat.go
+++ b/packages/eventindexer/repo/stat.go
@@ -33,12 +33,12 @@ func (r *StatRepository) Save(ctx context.Context, opts eventindexer.SaveStatOpt
 
 	if opts.ProofReward != nil {
 		s.NumVerifiedBlocks++
-		s.AverageProofReward = *opts.ProofReward
+		s.AverageProofReward = opts.ProofReward.String()
 	}
 
 	if opts.ProofTime != nil {
 		s.NumProofs++
-		s.AverageProofTime = *opts.ProofTime
+		s.AverageProofTime = opts.ProofTime.String()
 	}
 
 	if err := r.db.GormDB().Save(s).Error; err != nil {
@@ -58,5 +58,13 @@ func (r *StatRepository) Find(ctx context.Context) (*eventindexer.Stat, error) {
 		return nil, errors.Wrap(err, "r.db.gormDB.FirstOrCreate")
 	}
 
+	if s.AverageProofReward == "" {
+		s.AverageProofReward = "0"
+	}
+
+	if s.AverageProofTime == "" {
+		s.AverageProofTime = "0"
+	}
+
 	return s, nil
 }
diff --git a/packages/eventindexer/repo/stat_test.go b/packages/eventindexer/repo/stat_test.go
index 1a5d4364eb..1c7d9128c3 100644
--- a/packages/eventindexer/repo/stat_test.go
+++ b/packages/eventindexer/repo/stat_test.go
@@ -2,6 +2,7 @@ package repo
 
 import (
 	"context"
+	"math/big"
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
@@ -18,7 +19,7 @@ func TestIntegration_Stat_Save(t *testing.T) {
 	statRepo, err := NewStatRepository(db)
 	assert.Equal(t, nil, err)
 
-	var proofReward uint64 = 4
+	var proofReward = big.NewInt(4)
 
 	tests := []struct {
 		name    string
@@ -28,7 +29,7 @@ func TestIntegration_Stat_Save(t *testing.T) {
 		{
 			"successProofReward",
 			eventindexer.SaveStatOpts{
-				ProofReward: &proofReward,
+				ProofReward: proofReward,
 			},
 			nil,
 		},
@@ -51,10 +52,10 @@ func TestIntegration_Stat_Find(t *testing.T) {
 	statRepo, err := NewStatRepository(db)
 	assert.Equal(t, nil, err)
 
-	var proofReward uint64 = 4
+	var proofReward = big.NewInt(4)
 
 	_, err = statRepo.Save(context.Background(), eventindexer.SaveStatOpts{
-		ProofReward: &proofReward,
+		ProofReward: proofReward,
 	})
 
 	assert.Equal(t, nil, err)
@@ -68,8 +69,8 @@ func TestIntegration_Stat_Find(t *testing.T) {
 			"success",
 			&eventindexer.Stat{
 				ID:                 1,
-				AverageProofReward: 4,
-				AverageProofTime:   0,
+				AverageProofReward: proofReward.String(),
+				AverageProofTime:   "0",
 				NumProofs:          0,
 				NumVerifiedBlocks:  1,
 			},
diff --git a/packages/eventindexer/stat.go b/packages/eventindexer/stat.go
index 57dc57ff1f..58752298b6 100644
--- a/packages/eventindexer/stat.go
+++ b/packages/eventindexer/stat.go
@@ -2,6 +2,7 @@ package eventindexer
 
 import (
 	"context"
+	"math/big"
 )
 
 // Event represents a stored EVM event. The fields will be serialized
@@ -9,16 +10,16 @@ import (
 // dependant on the name of the event
 type Stat struct {
 	ID                 int    `json:"id"`
-	AverageProofTime   uint64 `json:"averageProofTime"`
-	AverageProofReward uint64 `json:"averageProofReward"`
+	AverageProofTime   string `json:"averageProofTime"`
+	AverageProofReward string `json:"averageProofReward"`
 	NumProofs          uint64 `json:"numProofs"`
 	NumVerifiedBlocks  uint64 `json:"numVerifiedBlocks"`
 }
 
 // SaveStatOpts
 type SaveStatOpts struct {
-	ProofTime   *uint64
-	ProofReward *uint64
+	ProofTime   *big.Int
+	ProofReward *big.Int
 }
 
 // StatRepository is used to interact with stats in the store