diff --git a/configure/CONFIG b/configure/CONFIG
index 8c07c1e60..cc2c4606b 100644
--- a/configure/CONFIG
+++ b/configure/CONFIG
@@ -22,7 +22,7 @@ EPICS_BASE = $(INSTALL_LOCATION)
 CONFIG = $(TOP)/configure
 BASE_TOP=YES
 else
-CONFIG = $(EPICS_BASE)/configure
+CONFIG ?= $(EPICS_BASE)/configure
 endif
 
 -include $(CONFIG)/os/CONFIG_COMPAT