diff --git a/src/CpintPlot.cpp b/src/CpintPlot.cpp
index 8cc67291b..7445d3e6b 100644
--- a/src/CpintPlot.cpp
+++ b/src/CpintPlot.cpp
@@ -67,7 +67,7 @@ bool
 is_ride_filename(const QString filename)
 {
     QRegExp re("^([0-9][0-9][0-9][0-9])_([0-9][0-9])_([0-9][0-9])"
-	       "_([0-9][0-9])_([0-9][0-9])_([0-9][0-9])\\.(raw|srm|csv|tcx|hrm)$");
+	       "_([0-9][0-9])_([0-9][0-9])_([0-9][0-9])\\.(raw|srm|csv|tcx|hrm|wko)$");
     return (re.exactMatch(filename));
 }