diff --git a/lib/gpx/segment.rb b/lib/gpx/segment.rb
index 0cb68d4..6b895d6 100644
--- a/lib/gpx/segment.rb
+++ b/lib/gpx/segment.rb
@@ -48,8 +48,10 @@ module GPX
             unless segment_element.is_a?(Text)
                XPath.each(segment_element, "child::trkpt") do |trkpt| 
                   pt = TrackPoint.new(:element => trkpt, :segment => self)  
-                  @earliest_point = pt if(@earliest_point.nil? or pt.time < @earliest_point.time)
-                  @latest_point   = pt if(@latest_point.nil? or pt.time > @latest_point.time)
+                  unless pt.time.nil?
+                     @earliest_point = pt if(@earliest_point.nil? or pt.time < @earliest_point.time)
+                     @latest_point   = pt if(@latest_point.nil? or pt.time > @latest_point.time)
+                  end
                   unless pt.elevation.nil?
                      @lowest_point   = pt if(@lowest_point.nil? or pt.elevation < @lowest_point.elevation)
                      @highest_point  = pt if(@highest_point.nil? or pt.elevation > @highest_point.elevation)