diff --git a/agrolib/project/interpolationCmd.h b/agrolib/project/interpolationCmd.h
index 96690dbcf..c592b5a7c 100644
--- a/agrolib/project/interpolationCmd.h
+++ b/agrolib/project/interpolationCmd.h
@@ -77,5 +77,6 @@
     bool interpolateProxyGridSeries(const Crit3DProxyGridSeries& mySeries, QDate myDate, const gis::Crit3DRasterGrid& gridBase,
                                     gis::Crit3DRasterGrid *gridOut, QString &errorStr);
 
+    bool topographicIndex(const gis::Crit3DRasterGrid DEM, std::vector <float> windowWidths, gis::Crit3DRasterGrid& outGrid);
 
 #endif // INTERPOLATIONCMD_H