--- linux-3.10/drivers/char/avm_new/generate-event-types
+++ linux-3.10/drivers/char/avm_new/generate-event-types
@@ -5,7 +5,7 @@
 cd "$1/avm_dist_event/"
 
 : ${PERL5LIB:=}
-export PERL5LIB="$PERL5LIB:."
+export PERL5LIB="${PERL5LIB:-}:."
 
 perl avm_event_generate.pl 1>/dev/null 2>&1
 cat avm_event_gen_types.h