diff --git a/src/grib_index.c b/src/grib_index.c
index bdb348814..00660f191 100644
--- a/src/grib_index.c
+++ b/src/grib_index.c
@@ -1168,7 +1168,8 @@ int _codes_index_add_file(grib_index* index, const char* filename, int message_t
                     return err;
             }
             if (err && err != GRIB_NOT_FOUND) {
-                grib_context_log(c, GRIB_LOG_ERROR, "unable to create index. \"%s\": %s", index_key->name, grib_get_error_message(err));
+                grib_context_log(c, GRIB_LOG_ERROR, "unable to create index. key=\"%s\" (message #%lu): %s",
+                                 index_key->name, message_count, grib_get_error_message(err));
                 return err;
             }
 
diff --git a/tools/bufr_index_build.c b/tools/bufr_index_build.c
index fdba3e100..aa5041f2d 100644
--- a/tools/bufr_index_build.c
+++ b/tools/bufr_index_build.c
@@ -151,7 +151,7 @@ int grib_tool_finalise_action(grib_runtime_options* options)
         printf(" }\n");
         the_keys = the_keys->next;
     }
-    printf("--- %d messages indexed\n", idx->count);
+    printf("--- %d message(s) indexed\n", idx->count);
 
     if (idx->count)
         grib_index_write(idx, options->outfile->name);
diff --git a/tools/grib_index_build.c b/tools/grib_index_build.c
index 0655905ca..24e959fbc 100644
--- a/tools/grib_index_build.c
+++ b/tools/grib_index_build.c
@@ -148,7 +148,7 @@ int grib_tool_finalise_action(grib_runtime_options* options)
         printf(" }\n");
         the_keys = the_keys->next;
     }
-    printf("--- %d messages indexed\n", idx->count);
+    printf("--- %d message(s) indexed\n", idx->count);
 
     if (idx->count)
         grib_index_write(idx, options->outfile->name);