diff --git a/transcoder/basisu_transcoder_internal.h b/transcoder/basisu_transcoder_internal.h
index 0505df6..aa3bee3 100644
--- a/transcoder/basisu_transcoder_internal.h
+++ b/transcoder/basisu_transcoder_internal.h
@@ -264,8 +264,8 @@ namespace basist
 		}
 
 		const basisu::uint8_vec &get_code_sizes() const { return m_code_sizes; }
-		const basisu::int_vec get_lookup() const { return m_lookup; }
-		const basisu::int16_vec get_tree() const { return m_tree; }
+		const basisu::int_vec &get_lookup() const { return m_lookup; }
+		const basisu::int16_vec &get_tree() const { return m_tree; }
 
 		bool is_valid() const { return m_code_sizes.size() > 0; }