diff --git a/raster/r.resamp.bspline/main.c b/raster/r.resamp.bspline/main.c
index 46d28cd174b..047a33f47df 100644
--- a/raster/r.resamp.bspline/main.c
+++ b/raster/r.resamp.bspline/main.c
@@ -707,6 +707,8 @@ int main(int argc, char *argv[])
 	    else {
 		if (observ)
 		    G_free(observ);
+		if (observ_marked)
+		    G_free(observ_marked);
 		if (npoints == 0)
 		    G_warning(_("No data within this subregion. "
 				"Consider increasing the spline step."));