diff --git a/cmd/util.go b/cmd/util.go
index 113f9f7..5b8d763 100644
--- a/cmd/util.go
+++ b/cmd/util.go
@@ -37,7 +37,7 @@ const (
 	// ProgramName is "elprep"
 	ProgramName = "elprep"
 	// ProgramVersion is the version of the elprep binary
-	ProgramVersion = "4.0.0"
+	ProgramVersion = "4.0.1"
 	// ProgramURL is the repository for the elprep source code
 	ProgramURL = "http://github.com/exascience/elprep"
 )
diff --git a/fasta/fasta-files.go b/fasta/fasta-files.go
index 4292579..06891b4 100644
--- a/fasta/fasta-files.go
+++ b/fasta/fasta-files.go
@@ -94,10 +94,16 @@ func ParseFai(filename string) (fai map[string]FaiReference, err error) {
 
 func contigFromHeader(b []byte) string {
 	i := 1
-	for ; (i < len(b)) && b[i] == ' '; i++ {
+	for ; i < len(b); i++ {
+		if c := b[i]; c >= '!' && c <= '~' {
+			break
+		}
 	}
 	j := i + 1
-	for ; (j < len(b)) && b[j] != ' '; j++ {
+	for ; j < len(b); j++ {
+		if c := b[j]; c < '!' || c > '~' {
+			break
+		}
 	}
 	return string(b[i:j])
 }