diff --git a/make/defs.mk b/make/defs.mk
index 8b20bea0..1a37140a 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -2,6 +2,9 @@
 # contact@jannet.de
 # $Id$
 
+ifndef YTOOLS_DEF_MK_INCLUDED
+YTOOLS_DEF_MK_INCLUDED = true
+
 # ----- pre-local.mk
 
 ifneq ($(wildcard $(MODDIR)/make/pre-local.mk),)
@@ -863,3 +866,4 @@ LDFLAGS                   += $(LOCAL_LDFLAGS) $(PROJECTLIB_LDFLAGS) $(PROJECT_LD
 RPM_REQUIRES              += $(RPM_REQUIRES_RUN) $(RPM_REQUIRES_DEVEL)
 NEW_LD_LIB_PATH            = $(shell echo $(LDFLAGS) | sed 's/[ 	]-[^L] *[^ ]*/ /g; s/-L[ ]*\([^ ]*\)[ ]*/\1:/g')
 
+endif