diff --git a/scanner/blocks.go b/scanner/blocks.go
index 86a277572..f6a957222 100644
--- a/scanner/blocks.go
+++ b/scanner/blocks.go
@@ -14,6 +14,8 @@ import (
 
 const StandardBlockSize = 128 * 1024
 
+var sha256OfNothing = []uint8{0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55}
+
 // Blocks returns the blockwise hash of the reader.
 func Blocks(r io.Reader, blocksize int) ([]protocol.BlockInfo, error) {
 	var blocks []protocol.BlockInfo
@@ -44,7 +46,7 @@ func Blocks(r io.Reader, blocksize int) ([]protocol.BlockInfo, error) {
 		blocks = append(blocks, protocol.BlockInfo{
 			Offset: 0,
 			Size:   0,
-			Hash:   []uint8{0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55},
+			Hash:   sha256OfNothing,
 		})
 	}