diff --git a/make/defs.mk b/make/defs.mk
index 8a459261..b1fcbc54 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -630,6 +630,16 @@ LIBFLAGS              += -L$(BUILD_LIBDIR)
 
 # -- use of supplementary libraries
 
+ifeq ($(USE_AUTH),true)
+AUTH_DIR                   = $(firstword $(wildcard $(CVS_PROJ_DIR)/auth /opt/$(FLAVOUR_PATH_PREFIX)auth))
+AUTH_VERSION               = $(call version,$(AUTH_DIR))
+RPM_REQUIRES_RUN          += $(FLAVOUR_PREFIX)auth-run = $(AUTH_VERSION)
+RPM_REQUIRES_DEVEL        += $(FLAVOUR_PREFIX)auth-devel = $(AUTH_VERSION)
+USE_YTOOLS                 = true
+INCLUDE                   += -I$(AUTH_DIR)/include
+LIBFLAGS                  += -L$(AUTH_DIR)/lib -lauth
+endif
+
 ifeq ($(USE_CCASFS),true)
 CCASFS_DIR                 = $(firstword $(wildcard $(CVS_PROJ_DIR)/dspc/src/ccasfs /opt/$(FLAVOUR_PATH_PREFIX)dspider/ccasfs))
 CCASFS_VERSION             = $(call version,$(CCASFS_DIR))