diff --git a/inftrees.h b/inftrees.h
@@ -30,7 +30,7 @@ typedef struct {
 /* op values as set by inflate_table():
     00000000 - literal
     0000tttt - table link, tttt != 0 is the number of table index bits
-    0001eeee - length or distance, eeee is the number of extra bits
+    0001eeee - length or distance, eeee is the number of non-extra bits
     01100000 - end of block
     01000000 - invalid code
  */