diff --git a/align/align.go b/align/align.go
index 491cad2..e6bde45 100644
--- a/align/align.go
+++ b/align/align.go
@@ -1295,7 +1295,7 @@ func (a *align) SiteConservation(position int) (conservation int, err error) {
 				}
 			}
 		}
-		if prevchar != ';' && sequence[position] != prevchar {
+		if (prevchar != ';' && sequence[position] != prevchar) || sequence[position] == GAP {
 			same = false
 		}
 		prevchar = sequence[position]
diff --git a/io/clustal/parser.go b/io/clustal/parser.go
index 8ec9605..219bae4 100644
--- a/io/clustal/parser.go
+++ b/io/clustal/parser.go
@@ -114,7 +114,7 @@ func (p *Parser) Parse() (align.Alignment, error) {
 			currentnbseqs = 0
 		}
 
-		if tok != IDENTIFIER {
+		if tok != IDENTIFIER && tok != NUMERIC {
 			return nil, errors.New("We expect a sequence identifier here")
 		}
 		name = lit