diff --git a/x/fbridge/keeper/grpc_query.go b/x/fbridge/keeper/grpc_query.go
index 3f6feb5d06..e2460064c2 100644
--- a/x/fbridge/keeper/grpc_query.go
+++ b/x/fbridge/keeper/grpc_query.go
@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"context"
+	"fmt"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -32,6 +33,12 @@ func (k Keeper) SeqToBlocknums(goCtx context.Context, req *types.QuerySeqToBlock
 		return nil, status.Error(codes.InvalidArgument, "empty request")
 	}
 
+	const lowerBound int = 1
+	const upperBound int = 1000
+	if len(req.Seqs) < lowerBound || len(req.Seqs) > upperBound {
+		return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("The number of seqs requested must be between %d and %d", lowerBound, upperBound))
+	}
+
 	ctx := sdk.UnwrapSDKContext(goCtx)
 	bhList := make([]uint64, len(req.Seqs))
 	for i, seq := range req.Seqs {