diff --git a/make/defs.mk b/make/defs.mk
index 49e85bb3..dab80e37 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -824,7 +824,7 @@ ifeq ($(USE_COMPILER_OPTIMIZATION_OPTS),true)
 	BUILD_CPPFLAGS    += -funroll-loops -O2
 else
 	NO_OPT_FLAGS = \
-		-g -fno-inline -fno-omit-frame-pointer -fno-builtin -fno-optimize-sibling-calls \
+		-O0 -g -fno-inline -fno-omit-frame-pointer -fno-builtin -fno-optimize-sibling-calls \
 		-fno-inline-functions-called-once \
 		-fno-tree-loop-optimize \
 		-fno-early-inlining
@@ -1289,6 +1289,18 @@ EXE_SEARCH_PATH           += $(USERVER_DIR)/bin
 PREREQ                    += USERVER
 endif
 
+ifneq ($(filter xchange-shell,$(PREREQ_BUILD)),)
+XCHANGE_SHELL_DIR           = $(firstword $(wildcard $(CVS_PROJ_DIR)/xchange-shell /opt/$(FLAVOUR_PATH_PREFIX)xchange-shell))
+XCHANGE_SHELL_VERSION       = $(call version,$(XCHANGE_SHELL_DIR))
+RPM_REQUIRES_RUN          += $(FLAVOUR_PREFIX)xchange-shell-run = $(XCHANGE_SHELL_VERSION)
+RPM_REQUIRES_DEVEL        += $(FLAVOUR_PREFIX)xchange-shell-devel = $(XCHANGE_SHELL_VERSION)
+PREREQ_BUILD              += xchange shell
+INCLUDE                   += -I$(XCHANGE_SHELL_DIR)/include
+LIBFLAGS                  += -L$(XCHANGE_SHELL_DIR)/lib -lxchange-shell
+EXE_SEARCH_PATH           += $(XCHANGE_SHELL_DIR)/bin
+PREREQ                    += XCHANGE_SHELL
+endif
+
 ifneq ($(filter xchange-pcap,$(PREREQ_BUILD)),)
 XCHANGE_PCAP_DIR           = $(firstword $(wildcard $(CVS_PROJ_DIR)/xchange-pcap /opt/$(FLAVOUR_PATH_PREFIX)xchange-pcap))
 XCHANGE_PCAP_VERSION       = $(call version,$(XCHANGE_PCAP_DIR))