diff --git a/src/grib_api_prototypes.h b/src/grib_api_prototypes.h
index cc7b0578b..129df97dd 100644
--- a/src/grib_api_prototypes.h
+++ b/src/grib_api_prototypes.h
@@ -746,6 +746,9 @@ grib_handle* grib_handle_new_from_index(grib_index* index, int* err);
 grib_handle* codes_new_from_index(grib_index* index, int message_type, int* err);
 void grib_index_rewind(grib_index* index);
 int grib_index_search(grib_index* index, grib_index_key* keys);
+int codes_index_set_product_kind(grib_index* index, ProductKind product_kind);
+int codes_index_set_unpack_bufr(grib_index* index, int unpack);
+int is_index_file(const char* filename);
 
 /* grib_accessor_class_number_of_points_gaussian.c */
 
@@ -1476,7 +1479,6 @@ int grib2_is_PDTN_ChemicalDistFunc(long productDefinitionTemplateNumber);
 int grib2_is_PDTN_Aerosol(long productDefinitionTemplateNumber);
 int grib2_is_PDTN_AerosolOptical(long productDefinitionTemplateNumber);
 int grib2_select_PDTN(int is_eps, int is_instant, int is_chemical, int is_chemical_distfn, int is_aerosol, int is_aerosol_optical);
-int is_index_file(const char* filename);
 size_t sum_of_pl_array(const long* pl, size_t plsize);
 int grib_is_earth_oblate(grib_handle* h);
 int grib_util_grib_data_quality_check(grib_handle* h, double min_val, double max_val);
diff --git a/src/grib_index.c b/src/grib_index.c
index f3a16ca85..dfe523335 100644
--- a/src/grib_index.c
+++ b/src/grib_index.c
@@ -1980,3 +1980,35 @@ int codes_index_set_unpack_bufr(grib_index* index, int unpack)
     index->unpack_bufr = unpack;
     return GRIB_SUCCESS;
 }
+
+/* Return 1 if the file is an index file. 0 otherwise */
+int is_index_file(const char* filename)
+{
+    FILE* fh;
+    char buf[8] = {0,};
+    const char* id_grib = "GRBIDX";
+    const char* id_bufr = "BFRIDX";
+    int ret         = 0;
+    size_t size     = 0;
+
+    fh = fopen(filename, "r");
+    if (!fh)
+        return 0;
+
+    size = fread(buf, 1, 1, fh);
+    if (size != 1) {
+        fclose(fh);
+        return 0;
+    }
+    size = fread(buf, 6, 1, fh);
+    if (size != 1) {
+        fclose(fh);
+        return 0;
+    }
+
+    ret = (strcmp(buf, id_grib)==0 || strcmp(buf, id_bufr)==0);
+
+    fclose(fh);
+
+    return ret;
+}
diff --git a/src/grib_util.c b/src/grib_util.c
index 011b5cfb7..15e182d9c 100644
--- a/src/grib_util.c
+++ b/src/grib_util.c
@@ -2141,37 +2141,6 @@ int grib2_select_PDTN(int is_eps, int is_instant,
     }
 }
 
-int is_index_file(const char* filename)
-{
-    FILE* fh;
-    char buf[8] = {0,};
-    const char* id_grib = "GRBIDX";
-    const char* id_bufr = "BFRIDX";
-    int ret         = 0;
-    size_t size     = 0;
-
-    fh = fopen(filename, "r");
-    if (!fh)
-        return 0;
-
-    size = fread(buf, 1, 1, fh);
-    if (size != 1) {
-        fclose(fh);
-        return 0;
-    }
-    size = fread(buf, 6, 1, fh);
-    if (size != 1) {
-        fclose(fh);
-        return 0;
-    }
-
-    ret = (strcmp(buf, id_grib)==0 || strcmp(buf, id_bufr)==0);
-
-    fclose(fh);
-
-    return ret;
-}
-
 size_t sum_of_pl_array(const long* pl, size_t plsize)
 {
     long i, count = 0;