diff --git a/tests/SE/regtest-3-2/N3-rp_colvar.inp b/tests/SE/regtest-3-2/N3-rp_colvar.inp
index 8bec040148..f67473975d 100644
--- a/tests/SE/regtest-3-2/N3-rp_colvar.inp
+++ b/tests/SE/regtest-3-2/N3-rp_colvar.inp
@@ -137,6 +137,7 @@
   &END SUBSYS
 &END FORCE_EVAL
 &GLOBAL
+  PREFERRED_DIAG_LIBRARY ScaLAPACK
   PROJECT N3-rp_colvar
   RUN_TYPE GEO_OPT
   PRINT_LEVEL LOW