diff --git a/api/gateway/chain/internal/service/gateway/commands/transfer/fee.go b/api/gateway/chain/internal/service/gateway/commands/transfer/fee.go
index 992e152..f622f8d 100644
--- a/api/gateway/chain/internal/service/gateway/commands/transfer/fee.go
+++ b/api/gateway/chain/internal/service/gateway/commands/transfer/fee.go
@@ -199,11 +199,17 @@ func erc20Decimals(ctx context.Context, client *rpc.Client, token common.Address
 	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
 		return 0, merrors.Internal("decimals call failed: " + err.Error())
 	}
-	val, err := hexutil.DecodeUint64(hexResp)
+	val, err := hexutil.DecodeBig(hexResp)
 	if err != nil {
 		return 0, merrors.Internal("decimals decode failed: " + err.Error())
 	}
-	return uint8(val), nil
+	if val == nil {
+		return 0, merrors.Internal("decimals decode failed: empty response")
+	}
+	if val.BitLen() > 8 {
+		return 0, merrors.Internal("decimals decode failed: value out of range")
+	}
+	return uint8(val.Uint64()), nil
 }
 
 func toBaseUnits(amount string, decimals uint8) (*big.Int, error) {
diff --git a/api/gateway/chain/internal/service/gateway/commands/wallet/onchain_balance.go b/api/gateway/chain/internal/service/gateway/commands/wallet/onchain_balance.go
index 8452237..61c1cdb 100644
--- a/api/gateway/chain/internal/service/gateway/commands/wallet/onchain_balance.go
+++ b/api/gateway/chain/internal/service/gateway/commands/wallet/onchain_balance.go
@@ -104,11 +104,17 @@ func readDecimals(ctx context.Context, client *rpc.Client, token string) (uint8,
 	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
 		return 0, merrors.Internal("decimals call failed: " + err.Error())
 	}
-	val, err := hexutil.DecodeUint64(hexResp)
+	val, err := hexutil.DecodeBig(hexResp)
 	if err != nil {
 		return 0, merrors.Internal("decimals decode failed: " + err.Error())
 	}
-	return uint8(val), nil
+	if val == nil {
+		return 0, merrors.Internal("decimals decode failed: empty response")
+	}
+	if val.BitLen() > 8 {
+		return 0, merrors.Internal("decimals decode failed: value out of range")
+	}
+	return uint8(val.Uint64()), nil
 }
 
 func readBalanceOf(ctx context.Context, client *rpc.Client, token string, wallet string) (*big.Int, error) {
diff --git a/api/gateway/chain/internal/service/gateway/executor.go b/api/gateway/chain/internal/service/gateway/executor.go
index bc5e25d..a76222e 100644
--- a/api/gateway/chain/internal/service/gateway/executor.go
+++ b/api/gateway/chain/internal/service/gateway/executor.go
@@ -315,11 +315,17 @@ func erc20Decimals(ctx context.Context, client *rpc.Client, token common.Address
 	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
 		return 0, executorInternal("decimals call failed", err)
 	}
-	val, err := hexutil.DecodeUint64(hexResp)
+	val, err := hexutil.DecodeBig(hexResp)
 	if err != nil {
 		return 0, executorInternal("decimals decode failed", err)
 	}
-	return uint8(val), nil
+	if val == nil {
+		return 0, executorInternal("decimals decode failed", errors.New("empty response"))
+	}
+	if val.BitLen() > 8 {
+		return 0, executorInternal("decimals decode failed", errors.New("value out of range"))
+	}
+	return uint8(val.Uint64()), nil
 }
 
 func toBaseUnits(amount string, decimals uint8) (*big.Int, error) {