diff --git a/configure/CONFIG_BASE b/configure/CONFIG_BASE
index 75b934714..d4a3f8a2e 100644
--- a/configure/CONFIG_BASE
+++ b/configure/CONFIG_BASE
@@ -13,8 +13,14 @@ EPICS_BASE_LIB      = $(EPICS_BASE)/lib/$(T_A)
 EPICS_BASE_BIN      = $(EPICS_BASE)/bin/$(T_A)
 endif
 
+#Definitions for extensions convenience
+as_DIR              = $(EPICS_BASE_LIB)
+ca_DIR              = $(EPICS_BASE_LIB)
 Db_DIR              = $(EPICS_BASE_LIB)
 Com_DIR             = $(EPICS_BASE_LIB)
+gdd_DIR             = $(EPICS_BASE_LIB)
+cas_DIR             = $(EPICS_BASE_LIB)
+
 
 #---------------------------------------------------------------
 # For applications and extensions