diff --git a/cmd/geth/chaincmd.go b/cmd/geth/chaincmd.go
index 61401dd59..3cae32aa9 100644
--- a/cmd/geth/chaincmd.go
+++ b/cmd/geth/chaincmd.go
@@ -322,6 +322,9 @@ func exportChain(ctx *cli.Context) error {
 		if first < 0 || last < 0 {
 			utils.Fatalf("Export error: block number must be greater than 0\n")
 		}
+		if head := chain.CurrentFastBlock(); uint64(last) > head.NumberU64() {
+			utils.Fatalf("Export error: block number %d larger than head block %d\n", uint64(last), head.NumberU64())
+		}
 		err = utils.ExportAppendChain(chain, fp, uint64(first), uint64(last))
 	}