diff --git a/server.go b/server.go
index 98b3bb3..9019b6b 100644
--- a/server.go
+++ b/server.go
@@ -260,6 +260,11 @@ func (s *Server) handleRegisteredCommand(command string, args []string) {
 			return
 		}
 
+		if s.upstream.State != libnmdc.CONNECTIONSTATE_CONNECTED {
+			s.reply(errCannotSend, args[0])
+			return
+		}
+
 		message := strings.Join(args[1:], " ")[1:] // strip leading colon
 
 		// IRC is case-insensitive case-preserving. We can respect that for the