diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 0b6b217..0024c99 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -2888,7 +2888,7 @@
 
 	switch (*p)
 	{
-	    // When adding an entry, also modify cmd_exists().
+	    // When adding an entry, also modify cmdmods[].
 	    case 'a':	if (!checkforcmd_noparen(&eap->cmd, "aboveleft", 3))
 			    break;
 			cmod->cmod_split |= WSP_ABOVE;
@@ -3958,11 +3958,13 @@
     {"confirm", 4, FALSE},
     {"filter", 4, FALSE},
     {"hide", 3, FALSE},
+    {"horizontal", 3, FALSE},
     {"keepalt", 5, FALSE},
     {"keepjumps", 5, FALSE},
     {"keepmarks", 3, FALSE},
     {"keeppatterns", 5, FALSE},
     {"leftabove", 5, FALSE},
+    {"legacy", 3, FALSE},
     {"lockmarks", 3, FALSE},
     {"noautocmd", 3, FALSE},
     {"noswapfile", 3, FALSE},
@@ -3974,6 +3976,7 @@
     {"unsilent", 3, FALSE},
     {"verbose", 4, TRUE},
     {"vertical", 4, FALSE},
+    {"vim9cmd", 4, FALSE},
 };
 
 /*