diff --git a/streaming/in.go b/streaming/in.go
index 474829a..0ecb29e 100644
--- a/streaming/in.go
+++ b/streaming/in.go
@@ -373,6 +373,8 @@ func (c *crypt4GHInternalReader) fillBuffer() error {
 	// reader should be positioned before the needed segment now
 
 	read, err := io.ReadFull(c.reader, encryptedSegmentBytes)
+	c.sourcePos += int64(read)
+
 	if err != nil && err != io.ErrUnexpectedEOF {
 		return err
 	}
@@ -391,7 +393,6 @@ func (c *crypt4GHInternalReader) fillBuffer() error {
 		return err
 	}
 	c.lastDecryptedSegment = neededSegment
-	c.sourcePos += int64(read)
 
 	// Keep track of how much data is directly available