diff --git a/configure/CONFIG b/configure/CONFIG
index 71226ff5c..89a64cbde 100644
--- a/configure/CONFIG
+++ b/configure/CONFIG
@@ -13,16 +13,14 @@ ifdef T_A
 -include $(TOP)/configure/RELEASE.$(EPICS_HOST_ARCH).$(T_A)
 endif
 
+BUILDING_LIBCOM = DEFINED
+
 CONFIG = $(RULES)/configure
 include $(CONFIG)/CONFIG
 
 # Override the Base definition:
 INSTALL_LOCATION = $(TOP)
 
-# Set location of locally generated tools
-EYACC = $(abspath $(INSTALL_HOST_BIN))/antelope$(HOSTEXE)
-ELEX = $(abspath $(INSTALL_HOST_BIN))/e_flex$(HOSTEXE) -S$(INSTALL_INCLUDE)/flex.skel.static
-
 # CONFIG_SITE files contain other build configuration settings
 include $(TOP)/configure/CONFIG_SITE
 -include $(TOP)/configure/CONFIG_SITE.$(EPICS_HOST_ARCH).Common
diff --git a/configure/CONFIG_LIBCOM_MODULE b/configure/CONFIG_LIBCOM_MODULE
new file mode 100644
index 000000000..175606cdb
--- /dev/null
+++ b/configure/CONFIG_LIBCOM_MODULE
@@ -0,0 +1,25 @@
+#*************************************************************************
+# Copyright (c) 2017 UChicago Argonne LLC, as Operator of Argonne
+#     National Laboratory.
+# EPICS BASE is distributed subject to a Software License Agreement found
+# in file LICENSE that is included with this distribution.
+#*************************************************************************
+
+# Set EPICS_LIBCOM if necessary
+ifndef EPICS_LIBCOM
+  EPICS_LIBCOM = $(if $(BUILDING_LIBCOM),$(INSTALL_LOCATION),$(EPICS_BASE))
+
+  # Paths to tools built here
+  EPICS_LIBCOM_HOST_BIN ?= $(EPICS_LIBCOM)/bin/$(EPICS_HOST_ARCH)
+endif
+
+# Set location of locally generated tools
+YACC = $(abspath $(EPICS_LIBCOM_HOST_BIN))/antelope$(HOSTEXE)
+LEX = $(abspath $(EPICS_LIBCOM_HOST_BIN))/e_flex$(HOSTEXE) \
+        -S$(EPICS_LIBCOM)/include/flex.skel.static
+
+# Default stack size for osiThread
+OSITHREAD_USE_DEFAULT_STACK = NO
+OSITHREAD_DEFAULT_STACK_FLAGS_YES = -DOSITHREAD_USE_DEFAULT_STACK
+
+BASE_CPPFLAGS += $(OSITHREAD_DEFAULT_STACK_FLAGS_$(OSITHREAD_USE_DEFAULT_STACK))
diff --git a/configure/Makefile b/configure/Makefile
index 925430940..85a7b5843 100644
--- a/configure/Makefile
+++ b/configure/Makefile
@@ -1,8 +1,15 @@
-TOP=..
+#*************************************************************************
+# EPICS BASE is distributed subject to a Software License Agreement found
+# in file LICENSE that is included with this distribution.
+#*************************************************************************
+TOP = ..
 
 include $(TOP)/configure/CONFIG
 
 TARGETS = $(CONFIG_TARGETS)
 CONFIGS += $(subst ../,,$(wildcard $(CONFIG_INSTALLS)))
 
+CFG += CONFIG_LIBCOM_MODULE
+CFG += CONFIG_LIBCOM_VERSION
+
 include $(TOP)/configure/RULES
diff --git a/src/Makefile b/src/Makefile
index 512bbf55f..020df7d5e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -9,7 +9,6 @@
 
 TOP = ..
 include $(TOP)/configure/CONFIG
-include $(TOP)/configure/CONFIG_LIBCOM_VERSION
 
 # Uncomment this to remove the (benign) valgrind helper stubs
 #USR_CFLAGS += -DNVALGRIND