diff --git a/src/eccodes_prototypes.h b/src/eccodes_prototypes.h
index a75d82d1a..d7479e960 100644
--- a/src/eccodes_prototypes.h
+++ b/src/eccodes_prototypes.h
@@ -466,7 +466,6 @@ long grib_julian_to_date(long jdate);
 long grib_date_to_julian(long ddate);
 
 /* grib_fieldset.cc */
-int grib_fieldset_new_column(grib_fieldset* set, int id, char* key, int type);
 grib_fieldset* grib_fieldset_new_from_files(grib_context* c, const char* filenames[], int nfiles, const char** keys, int nkeys, const char* where_string, const char* order_by_string, int* err);
 int grib_fieldset_apply_where(grib_fieldset* set, const char* where_string);
 int grib_fieldset_apply_order_by(grib_fieldset* set, const char* order_by_string);
diff --git a/src/grib_fieldset.cc b/src/grib_fieldset.cc
index 72cb928c6..a37013844 100644
--- a/src/grib_fieldset.cc
+++ b/src/grib_fieldset.cc
@@ -55,7 +55,7 @@ static int grib_fieldset_set_order_by(grib_fieldset* set, grib_order_by* ob);
 
 
 /* --------------- grib_column functions ------------------*/
-int grib_fieldset_new_column(grib_fieldset* set, int id, char* key, int type)
+static int grib_fieldset_new_column(grib_fieldset* set, int id, char* key, int type)
 {
     grib_column* column = NULL;
     grib_context* c;