diff --git a/include/client.h b/include/client.h
index 6a50f5339..805f8599d 100644
--- a/include/client.h
+++ b/include/client.h
@@ -234,6 +234,9 @@ struct LocalUser
 	/* nicknames theyre monitoring */
 	rb_dlink_list monitor_list;
 
+	/* collects umodes explicitly changed by this user */
+	unsigned int changed_umodes;
+
 	/*
 	 * Anti-flood stuff. We track how many messages were parsed and how
 	 * many we were allowed in the current second, and apply a simple decay
diff --git a/include/s_user.h b/include/s_user.h
index 8e81f4a28..8ed9c1050 100644
--- a/include/s_user.h
+++ b/include/s_user.h
@@ -38,6 +38,7 @@ extern bool valid_username(const char *username);
 extern int user_mode(struct Client *, struct Client *, int, const char **);
 extern void send_umode(struct Client *, struct Client *, int, char *);
 extern void send_umode_out(struct Client *, struct Client *, int);
+extern void change_default_umodes(struct Client *);
 extern void show_lusers(struct Client *source_p);
 extern int register_local_user(struct Client *, struct Client *);
 
@@ -55,6 +56,6 @@ struct PrivilegeSet;
 extern void report_priv_change(struct Client *, struct PrivilegeSet *, struct PrivilegeSet *);
 extern void oper_up(struct Client *, struct oper_conf *);
 
-#endif
-
 extern bool has_common_channel(struct Client *source_p, struct Client *target_p);
+
+#endif
diff --git a/ircd/s_conf.c b/ircd/s_conf.c
index cb86811ff..2d4ba795c 100644
--- a/ircd/s_conf.c
+++ b/ircd/s_conf.c
@@ -653,6 +653,7 @@ bool
 rehash(bool sig)
 {
 	rb_dlink_node *n;
+	int old_umodes;
 
 	hook_data_rehash hdata = { sig };
 
@@ -664,6 +665,10 @@ rehash(bool sig)
 
 	privilegeset_prepare_rehash();
 
+	/* capture current set of default umodes; if this changes we'll apply the
+	 * change to all local clients */
+	old_umodes = ConfigFileEntry.default_umodes;
+
 	/* don't close listeners until we know we can go ahead with the rehash */
 	read_conf_files(false);
 
@@ -683,6 +688,15 @@ rehash(bool sig)
 
 	privilegeset_cleanup_rehash();
 
+	if (old_umodes != ConfigFileEntry.default_umodes)
+		RB_DLINK_FOREACH(n, lclient_list.head)
+		{
+			struct Client *client = n->data;
+			if (!IsPerson(client))
+				continue;
+			change_default_umodes(client);
+		}
+
 	call_hook(h_rehash, &hdata);
 	return false;
 }
diff --git a/ircd/s_user.c b/ircd/s_user.c
index d758b537c..223ed23ee 100644
--- a/ircd/s_user.c
+++ b/ircd/s_user.c
@@ -1089,6 +1089,7 @@ user_mode(struct Client *client_p, struct Client *source_p, int parc, const char
 	const char *pm;
 	struct Client *target_p;
 	int what, setflags;
+	int changemask = 0;
 	bool badflag = false;	/* Only send one bad flag notice */
 	bool showsnomask = false;
 	unsigned int setsnomask;
@@ -1279,6 +1280,7 @@ user_mode(struct Client *client_p, struct Client *source_p, int parc, const char
 						source_p->umodes |= flag;
 					else
 						source_p->umodes &= ~flag;
+					changemask |= flag;
 				}
 			}
 			else
@@ -1336,6 +1338,17 @@ user_mode(struct Client *client_p, struct Client *source_p, int parc, const char
 		++Count.invisi;
 	if((setflags & UMODE_INVISIBLE) && !IsInvisible(source_p))
 		--Count.invisi;
+
+	/* mark changed umodes so that if default umodes change, these don't get touched */
+	if (MyClient(source_p))
+	{
+		/* capture modes the user listed in the string, even if they were already (un)set,
+		 * e.g. /umode -R when they were already -R */
+		source_p->localClient->changed_umodes |= changemask;
+		/* all changed modes, whether through the user directly or as a result of a hook */
+		source_p->localClient->changed_umodes |= source_p->umodes ^ setflags;
+	}
+
 	/*
 	 * compare new flags with old flags and send string which
 	 * will cause servers to update correctly.
@@ -1432,6 +1445,37 @@ send_umode_out(struct Client *client_p, struct Client *source_p, int old)
 		send_umode(client_p, source_p, old, buf);
 }
 
+/*
+ * change_default_umodes
+ *
+ * inputs   - pointer to local client
+ * outputs  - NONE
+ * side effects - changes the user's umodes to correspond to the new defaults
+ */
+void
+change_default_umodes(struct Client *client_p)
+{
+	struct ConfItem *a_conf;
+	unsigned int old, new_default, changed_mask;
+
+	if (!MyClient(client_p))
+		return;
+
+	a_conf = client_p->localClient->att_conf;
+	old = client_p->umodes;
+	changed_mask = client_p->localClient->changed_umodes;
+
+	new_default = ConfigFileEntry.default_umodes & ~a_conf->umodes_mask;
+	new_default |= a_conf->umodes;
+	new_default &= ~orphaned_umodes;
+	if (!IsOper(client_p))
+		new_default &= ~ConfigFileEntry.oper_only_umodes;
+
+	client_p->umodes = (new_default & ~changed_mask) | (old & changed_mask);
+	if (client_p->umodes != old)
+		send_umode_out(client_p, client_p, old);
+}
+
 /*
  * user_welcome
  *