diff --git a/packages/eventindexer/indexer/save_block_proven_event.go b/packages/eventindexer/indexer/save_block_proven_event.go
index b2ded916ef6..ecc1167c4c1 100644
--- a/packages/eventindexer/indexer/save_block_proven_event.go
+++ b/packages/eventindexer/indexer/save_block_proven_event.go
@@ -104,8 +104,13 @@ func (svc *Service) updateAverageProofTime(ctx context.Context, event *taikol1.T
 
 	proofTime := provenAt - proposedAt
 
+	avg, ok := new(big.Int).SetString(stat.AverageProofTime, 10)
+	if !ok {
+		return errors.New("unable to convert average proof time to string")
+	}
+
 	newAverageProofTime := calcNewAverage(
-		stat.AverageProofTime,
+		avg,
 		new(big.Int).SetUint64(stat.NumProofs),
 		new(big.Int).SetUint64(proofTime),
 	)
diff --git a/packages/eventindexer/indexer/save_block_verified_event.go b/packages/eventindexer/indexer/save_block_verified_event.go
index b1eba79cab3..e242b1ee54b 100644
--- a/packages/eventindexer/indexer/save_block_verified_event.go
+++ b/packages/eventindexer/indexer/save_block_verified_event.go
@@ -80,8 +80,13 @@ func (svc *Service) updateAverageBlockReward(ctx context.Context, event *taikol1
 		return errors.Wrap(err, "svc.statRepo.Find")
 	}
 
+	avg, ok := new(big.Int).SetString(stat.AverageProofReward, 10)
+	if !ok {
+		return errors.New("unable to convert average proof reward to string")
+	}
+
 	newAverageProofReward := calcNewAverage(
-		stat.AverageProofReward,
+		avg,
 		new(big.Int).SetUint64(stat.NumVerifiedBlocks),
 		new(big.Int).SetUint64(reward),
 	)
diff --git a/packages/eventindexer/migrations/1666650701_create_stats_table.sql b/packages/eventindexer/migrations/1666650701_create_stats_table.sql
index 9359c113302..9a8ea8a6e93 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 bigint NOT NULL DEFAULT 0,
-    average_proof_reward bigint 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 c3bafb3257b..f49d29b01f2 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 0d6492620cb..400d13768e5 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 {
diff --git a/packages/eventindexer/repo/stat_test.go b/packages/eventindexer/repo/stat_test.go
index f5c1590a30c..1c7d9128c3a 100644
--- a/packages/eventindexer/repo/stat_test.go
+++ b/packages/eventindexer/repo/stat_test.go
@@ -69,8 +69,8 @@ func TestIntegration_Stat_Find(t *testing.T) {
 			"success",
 			&eventindexer.Stat{
 				ID:                 1,
-				AverageProofReward: proofReward,
-				AverageProofTime:   big.NewInt(0),
+				AverageProofReward: proofReward.String(),
+				AverageProofTime:   "0",
 				NumProofs:          0,
 				NumVerifiedBlocks:  1,
 			},
diff --git a/packages/eventindexer/stat.go b/packages/eventindexer/stat.go
index bd5298d9541..58752298b66 100644
--- a/packages/eventindexer/stat.go
+++ b/packages/eventindexer/stat.go
@@ -9,11 +9,11 @@ import (
 // into the Data field to be unmarshalled into a concrete struct
 // dependant on the name of the event
 type Stat struct {
-	ID                 int      `json:"id"`
-	AverageProofTime   *big.Int `json:"averageProofTime"`
-	AverageProofReward *big.Int `json:"averageProofReward"`
-	NumProofs          uint64   `json:"numProofs"`
-	NumVerifiedBlocks  uint64   `json:"numVerifiedBlocks"`
+	ID                 int    `json:"id"`
+	AverageProofTime   string `json:"averageProofTime"`
+	AverageProofReward string `json:"averageProofReward"`
+	NumProofs          uint64 `json:"numProofs"`
+	NumVerifiedBlocks  uint64 `json:"numVerifiedBlocks"`
 }
 
 // SaveStatOpts