diff --git a/modules/Bio/EnsEMBL/DBSQL/SequenceAdaptor.pm b/modules/Bio/EnsEMBL/DBSQL/SequenceAdaptor.pm
index 0d30a7fa907b99ecf5fc88c1bff69bae1a9cff27..dc358483842e0d2a6fc4bfef0aee0dd9f28bdcd0 100644
--- a/modules/Bio/EnsEMBL/DBSQL/SequenceAdaptor.pm
+++ b/modules/Bio/EnsEMBL/DBSQL/SequenceAdaptor.pm
@@ -146,7 +146,7 @@ sub fetch_by_Slice_start_end_strand {
 
    $start = 1 if(!defined($start));
  
-   if ( ( $start > $end || $start < 0 || $end < 0 || $slice->start> $slice->end ) && $slice->is_circular ) {
+   if ( ( !defined($end) || $start > $end || $start < 0 || $end < 0 || $slice->start> $slice->end ) && $slice->is_circular ) {
        if ($start > $end ) {
            return $self->_fetch_by_Slice_start_end_strand_circular( $slice, $start, $end, $strand );
        }
@@ -158,6 +158,9 @@ sub fetch_by_Slice_start_end_strand {
            $end += $slice->seq_region_length;
        }
 
+       if ( !defined($end) ) {	 
+       }
+
        if($slice->start> $slice->end) {
            return $self->_fetch_by_Slice_start_end_strand_circular( $slice, $slice->start, $slice->end, $strand );
        }