diff --git a/src/chelp/grid/GNUmakefile b/src/chelp/grid/GNUmakefile
index fe15c94b06..22b0f5add0 100644
--- a/src/chelp/grid/GNUmakefile
+++ b/src/chelp/grid/GNUmakefile
@@ -6,6 +6,8 @@
                  chelp_atom_rad.o\
                  chelp_grid_data.o
 
+USES_BLAS = chelp_grid.F chelp_grid_data.F
+
 LIBRARY=libchelp.a
 
 HEADERS=