diff --git a/lib/format_text/export.c b/lib/format_text/export.c
index 6164b71dc..ba58e4cd4 100644
--- a/lib/format_text/export.c
+++ b/lib/format_text/export.c
@@ -394,6 +394,8 @@ static char *_alloc_printed_str_list(struct dm_list *list)
 		return NULL;
 	}
 
+	buffer[0];
+
 	dm_list_iterate_items(sl, list) {
 		if (!emit_to_buffer(&buf, &size, "%s\"%s\"",
 				    (!first) ? ", " : "",
@@ -839,6 +841,7 @@ static int _alloc_printed_indirect_descendants(struct dm_list *indirect_glvs, ch
 		return 0;
 	}
 	buf = *buffer;
+	buf[0] = 0;
 
 	dm_list_iterate_items(user_glvl, indirect_glvs) {
 		if (user_glvl->glv->is_historical)
diff --git a/lib/format_text/flags.c b/lib/format_text/flags.c
index b4debe398..5973407b7 100644
--- a/lib/format_text/flags.c
+++ b/lib/format_text/flags.c
@@ -145,6 +145,9 @@ int print_flags(char *buffer, size_t size, enum pv_vg_lv_e type, int mask, uint6
 	if (!(flags = _get_flags(type)))
 		return_0;
 
+	if (size)
+		buffer[0] = 0;
+
 	for (f = 0; flags[f].mask; f++) {
 		if (status & flags[f].mask) {
 			status &= ~flags[f].mask;