diff --git a/src/if_mzsch.c b/src/if_mzsch.c
index c325a92..a175b6e 100644
--- a/src/if_mzsch.c
+++ b/src/if_mzsch.c
@@ -2027,7 +2027,7 @@
     extra = 0;
 
     check_line_range(lo, buf->buf);	    /* inclusive */
-    check_line_range(hi - 1, buf->buf);  /* exclisive */
+    check_line_range(hi - 1, buf->buf);	    /* exclusive */
 
     if (SCHEME_FALSEP(line_list) || SCHEME_NULLP(line_list))
     {