diff --git a/src/mark.c b/src/mark.c
index ca64c90..298da67 100644
--- a/src/mark.c
+++ b/src/mark.c
@@ -1442,7 +1442,7 @@
 
     list_append_number(lpos, bufnr);
     list_append_number(lpos, pos->lnum);
-    list_append_number(lpos, pos->col);
+    list_append_number(lpos, pos->col + 1);
     list_append_number(lpos, pos->coladd);
 
     if (dict_add_string(d, "mark", mname) == FAIL