diff --git a/lib/PBot/EventDispatcher.pm b/lib/PBot/EventDispatcher.pm
index 1c9ac38f..cbf24a5b 100644
--- a/lib/PBot/EventDispatcher.pm
+++ b/lib/PBot/EventDispatcher.pm
@@ -22,6 +22,14 @@ sub initialize {
 }
 
 # add an event handler
+#
+# priority ranges from 0 to 100. 0 is the highest priority, i.e. an handler with
+# priority 0 will handle events first. 100 is the lowest priority and will handle
+# events last. priority defaults to 50 if ommited.
+#
+# NickList reserves 0 and 100 to ensure its list is populated by JOINs, etc,
+# before any handlers need to consult its list, or depopulated by PARTs, QUITs,
+# KICKs, etc, after any other handlers need to consult its list.
 sub register_handler {
     my ($self, $event_name, $subref, $priority) = @_;
 
@@ -108,13 +116,13 @@ sub dispatch_event {
             # that it decided not to handle this event.
             my $handler_result = eval { $handler->{subref}->($event_name, $event_data) };
 
-            # update $dispatch_result only when handler result is a defined
-            # value so we remember if any handlers have handled this event.
-            $dispatch_result = $handler_result if defined $handler_result;
-
             # check for exception
             if (my $exception = $@) {
                 $self->{pbot}->{logger}->log("Exception in event handler: $exception");
+            } else {
+                # update $dispatch_result only when handler result is a defined
+                # value so we remember if any handlers have handled this event.
+                $dispatch_result = $handler_result if defined $handler_result;
             }
         }
     }
diff --git a/lib/PBot/NickList.pm b/lib/PBot/NickList.pm
index 065312df..b20a9a27 100644
--- a/lib/PBot/NickList.pm
+++ b/lib/PBot/NickList.pm
@@ -34,19 +34,26 @@ sub initialize {
     $self->{pbot}->{commands}->register(sub { $self->cmd_nicklist(@_) }, "nicklist", 1);
 
     # handlers for various IRC events
+
     # TODO: track mode changes to update user flags
     # Update: turns out that IRCHandler's on_mode() is doing this already -- we need to make that
     # emit a mode-change event or some such and register a handler for it here.
+
+    # lowest priority so these get handled by NickList before any other handlers
+    # (all other handlers should be given a priority > 0)
     $self->{pbot}->{event_dispatcher}->register_handler('irc.namreply', sub { $self->on_namreply(@_) },   0   );
     $self->{pbot}->{event_dispatcher}->register_handler('irc.join',     sub { $self->on_join(@_) },       0   );
+    $self->{pbot}->{event_dispatcher}->register_handler('irc.public',   sub { $self->on_activity(@_) },   0   );
+    $self->{pbot}->{event_dispatcher}->register_handler('irc.caction',  sub { $self->on_activity(@_) },   0   );
+
+    # highest priority so these get handled by NickList after all other handlers
+    # (all other handlers should be given a priority < 100)
     $self->{pbot}->{event_dispatcher}->register_handler('irc.part',     sub { $self->on_part(@_) },       100 );
     $self->{pbot}->{event_dispatcher}->register_handler('irc.quit',     sub { $self->on_quit(@_) },       100 );
     $self->{pbot}->{event_dispatcher}->register_handler('irc.kick',     sub { $self->on_kick(@_) },       100 );
     $self->{pbot}->{event_dispatcher}->register_handler('irc.nick',     sub { $self->on_nickchange(@_) }, 100 );
-    $self->{pbot}->{event_dispatcher}->register_handler('irc.public',   sub { $self->on_activity(@_) },   0   );
-    $self->{pbot}->{event_dispatcher}->register_handler('irc.caction',  sub { $self->on_activity(@_) },   0   );
 
-    # handlers for the bot itself joining/leaving channels
+    # handlers for the bot itself joining/leaving channels (lowest priority)
     $self->{pbot}->{event_dispatcher}->register_handler('pbot.join', sub { $self->on_self_join(@_) }, 0);
     $self->{pbot}->{event_dispatcher}->register_handler('pbot.part', sub { $self->on_self_part(@_) }, 0);
 }