diff --git a/demos/bio/Makefile b/demos/bio/Makefile
index 5a4e4a4ae2..86f19d4df3 100644
--- a/demos/bio/Makefile
+++ b/demos/bio/Makefile
@@ -28,3 +28,6 @@ server-conf: server-conf.o
 
 client-arg client-conf saccept sconnect server-arg server-cmod server-conf:
 	$(CC) $(CFLAGS) -o $@ $< $(LDFLAGS)
+
+clean:
+	$(RM) *.o client-arg client-conf saccept sconnect server-arg server-cmod server-conf