diff --git a/rtl/embedded/rtl.cfg b/rtl/embedded/rtl.cfg
index 952e376d2c..1d38abc785 100644
--- a/rtl/embedded/rtl.cfg
+++ b/rtl/embedded/rtl.cfg
@@ -5,6 +5,7 @@
 -SfTEXTIO
 -SfFILEIO
 -SfHEAP
+
 # uncomment to enable the stuff you want to use
 
 # include full heap management into the rtl
@@ -105,3 +106,12 @@
 -SfRANDOM
 -SfRESOURCES
 #endif CPUMIPSEL
+
+# does not require extra memory, neither code nor data
+# in programs not using e. g. writeln based I/O which is the common case for AVR
+#ifdef CPUAVR
+-SfOBJECTS
+-SfEXCEPTIONS
+-SfCLASSES
+-SfRTTI
+#endif