diff --git a/src/bitvec.c b/src/bitvec.c
index 10aa776..6202227 100644
--- a/src/bitvec.c
+++ b/src/bitvec.c
@@ -292,7 +292,7 @@
 	return 0;
 }
 
-/*! pad all remaining bits up to num_bits
+/*! pad all remaining bits up to a given bit number
  *  \return 0 on success; negative otherwise */
 int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit)
 {