diff --git a/x/observer/keeper/voting.go b/x/observer/keeper/voting.go
index 1f624da5aa..51286665c8 100644
--- a/x/observer/keeper/voting.go
+++ b/x/observer/keeper/voting.go
@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"fmt"
+	"github.com/pkg/errors"
 
 	sdkerrors "cosmossdk.io/errors"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -134,12 +135,12 @@ func (k Keeper) CheckObserverSelfDelegation(ctx sdk.Context, accAddress string)
 	}
 	validator, found := k.stakingKeeper.GetValidator(ctx, valAddress)
 	if !found {
-		return types.ErrNotValidator
+		return errors.Wrapf(types.ErrNotValidator, "validator : %s", valAddress)
 	}
 
 	delegation, found := k.stakingKeeper.GetDelegation(ctx, selfdelAddr, valAddress)
 	if !found {
-		return types.ErrSelfDelegation
+		return errors.Wrapf(types.ErrSelfDelegation, "self delegation : %s , valAddres : %s", selfdelAddr, valAddress)
 	}
 
 	minDelegation, err := types.GetMinObserverDelegationDec()