diff --git a/gpxsee.pro b/gpxsee.pro
index befab9ef..567efc7e 100644
--- a/gpxsee.pro
+++ b/gpxsee.pro
@@ -563,7 +563,8 @@ win32 {
         icons/formats/trk.ico \
         icons/formats/gemf.ico \
         icons/formats/000.ico \
-        icons/formats/031.ico
+        icons/formats/031.ico \
+        icons/formats/vtk.ico
     DEFINES += _USE_MATH_DEFINES \
         NOGDI
 }
diff --git a/icons/formats/scripts/extensions b/icons/formats/scripts/extensions
index fe2efac9..9548ca02 100644
--- a/icons/formats/scripts/extensions
+++ b/icons/formats/scripts/extensions
@@ -32,3 +32,4 @@ trk:#cccccc
 gemf:#147085
 000:#000000
 031:#000000
+vtk:#632433
diff --git a/icons/formats/vtk.ico b/icons/formats/vtk.ico
new file mode 100644
index 00000000..ce743567
Binary files /dev/null and b/icons/formats/vtk.ico differ
diff --git a/pkg/windows/gpxsee64.nsi b/pkg/windows/gpxsee64.nsi
index 824409cb..57e2b3d9 100644
--- a/pkg/windows/gpxsee64.nsi
+++ b/pkg/windows/gpxsee64.nsi
@@ -204,13 +204,14 @@ Section "GPXSee" SEC_APP
   !insertmacro FILE_ASSOCIATION_ADD "gemf" "GEMF Map File" 26
   !insertmacro FILE_ASSOCIATION_ADD "000" "IHO S-57 Electronic Navigation Chart" 27
   !insertmacro FILE_ASSOCIATION_ADD "031" "IHO S-57 Electronic Navigation Catalogue" 28
-  !insertmacro FILE_ASSOCIATION_ADD "kml" "Keyhole Markup Language" 29
-  !insertmacro FILE_ASSOCIATION_ADD "kmz" "KML geographic compressed data" 29
-  !insertmacro FILE_ASSOCIATION_ADD "fit" "Flexible and Interoperable Data Transfer" 30
-  !insertmacro FILE_ASSOCIATION_ADD "igc" "Flight Recorder Data Format" 31
-  !insertmacro FILE_ASSOCIATION_ADD "nmea" "NMEA 0183 Data" 32
-  !insertmacro FILE_ASSOCIATION_ADD "plt" "OziExplorer Track File" 33
-  !insertmacro FILE_ASSOCIATION_ADD "rte" "OziExplorer Route File" 34
+  !insertmacro FILE_ASSOCIATION_ADD "vtk" "Velocitek VTK File" 29
+  !insertmacro FILE_ASSOCIATION_ADD "kml" "Keyhole Markup Language" 30
+  !insertmacro FILE_ASSOCIATION_ADD "kmz" "KML geographic compressed data" 30
+  !insertmacro FILE_ASSOCIATION_ADD "fit" "Flexible and Interoperable Data Transfer" 31
+  !insertmacro FILE_ASSOCIATION_ADD "igc" "Flight Recorder Data Format" 32
+  !insertmacro FILE_ASSOCIATION_ADD "nmea" "NMEA 0183 Data" 33
+  !insertmacro FILE_ASSOCIATION_ADD "plt" "OziExplorer Track File" 34
+  !insertmacro FILE_ASSOCIATION_ADD "rte" "OziExplorer Route File" 35
 
   !insertmacro URI_ASSOCIATION_ADD "geo"
 
@@ -266,6 +267,7 @@ Section "GPXSee" SEC_APP
   WriteRegStr HKCR ".000\OpenWithList" "GPXSee.exe" ""
   WriteRegStr HKCR ".031\OpenWithList" "GPXSee.exe" ""
   WriteRegStr HKCR ".txt\OpenWithList" "GPXSee.exe" ""
+  WriteRegStr HKCR ".vtk\OpenWithList" "GPXSee.exe" ""
 
   System::Call 'shell32.dll::SHChangeNotify(i, i, i, i) v (0x08000000, 0, 0, 0)'
 
@@ -440,6 +442,7 @@ Section "Uninstall"
   !insertmacro FILE_ASSOCIATION_REMOVE "gemf"
   !insertmacro FILE_ASSOCIATION_REMOVE "000"
   !insertmacro FILE_ASSOCIATION_REMOVE "031"
+  !insertmacro FILE_ASSOCIATION_REMOVE "vtk"
 
   !insertmacro URI_ASSOCIATION_REMOVE "geo"
 
@@ -494,6 +497,7 @@ Section "Uninstall"
   DeleteRegValue HKCR ".000\OpenWithList" "GPXSee.exe"
   DeleteRegValue HKCR ".031\OpenWithList" "GPXSee.exe"
   DeleteRegValue HKCR ".txt\OpenWithList" "GPXSee.exe"
+  DeleteRegValue HKCR ".vtk\OpenWithList" "GPXSee.exe"
   DeleteRegKey HKCR "Applications\GPXSee.exe"   
   
   System::Call 'shell32.dll::SHChangeNotify(i, i, i, i) v (0x08000000, 0, 0, 0)'