diff --git a/data-access/engine/src/vlkb-obscore/src/database/SqlSurvey.cpp b/data-access/engine/src/vlkb-obscore/src/database/SqlSurvey.cpp
index 2f45de03b8be407bb598106ec529b27cb94023d3..99a01a005cc54377f5fdc1a7ad347aa1f101d126 100644
--- a/data-access/engine/src/vlkb-obscore/src/database/SqlSurvey.cpp
+++ b/data-access/engine/src/vlkb-obscore/src/database/SqlSurvey.cpp
@@ -75,7 +75,7 @@ string to_sql_values(survey surv)
       + to_string(surv.rest_frequency_Hz) + ", "
       + to_sqlstring2("") + ", "
       // FIXME NOT USED + to_sqlstring2(surv.restf_fits_unit) + ", "
-      + to_sqlstring2(to_string(surv.velocity_fits_unit)) + ", "
+      + (surv.velocity_fits_unit == velocity_unit::NONE ? "NULL" : to_sqlstring2(to_string(surv.velocity_fits_unit))) + ", "
       + to_sqlstring2(surv.storage_path) + ", "
       + to_sqlstring2(surv.file_filter) + ", "
       + to_sqlstring2(surv.description) + ", "