diff --git a/include/ucore/bitvec.h b/include/ucore/bitvec.h
index af11d67..acbedaa 100644
--- a/include/ucore/bitvec.h
+++ b/include/ucore/bitvec.h
@@ -8,7 +8,7 @@ extern "C" {
 struct UCBitVec {
     //storage for the bits
     unsigned long *vec;
-    //length of the above vec. (Not the number of bits !)
+    //length in bytes of the above vec.
     size_t vec_len;
 };