diff --git a/Makefile.defs b/Makefile.defs
index 13ee8931..8509e207 100644
--- a/Makefile.defs
+++ b/Makefile.defs
@@ -32,7 +32,7 @@ endif
 GPP ?= g++
 GCC ?= gcc
 
-CXX_FLAGS = -Wall -Wno-reorder -fPIC -g \
+CXX_FLAGS ?= -Wall -Wno-reorder -fPIC -g \
 	  -O2 \
 	  -D_DEBUG \
 	  -D_THREAD_SAFE -D_REENTRANT \
@@ -40,7 +40,7 @@ CXX_FLAGS = -Wall -Wno-reorder -fPIC -g \
 	  -DOS='"$(OS)"' 	\
 #	  -DSUPPORT_IPV6
 
-C_FLAGS = -Wall -fPIC -g \
+C_FLAGS ?= -Wall -fPIC -g \
 	  -O2 \
 	  -D_DEBUG \
 	  -D_THREAD_SAFE -D_REENTRANT \
diff --git a/core/plug-in/Makefile.audio_module b/core/plug-in/Makefile.audio_module
index 39e7dfaf..4cddfd98 100644
--- a/core/plug-in/Makefile.audio_module
+++ b/core/plug-in/Makefile.audio_module
@@ -2,7 +2,7 @@ COREPATH ?=../..
 include $(COREPATH)/../Makefile.defs
 
 ldflags = -shared $(module_ldflags)
-cflags  = -fPIC -I $(COREPATH) -I $(COREPATH)/amci -Wall $(module_cflags)
+cflags  = $(C_FLAGS) -I $(COREPATH) -I $(COREPATH)/amci -Wall $(module_cflags)
 
 audio_mod_dir = $(COREPATH)/lib
 
diff --git a/core/plug-in/ilbc/Makefile b/core/plug-in/ilbc/Makefile
index 4492f46f..46a1977f 100644
--- a/core/plug-in/ilbc/Makefile
+++ b/core/plug-in/ilbc/Makefile
@@ -35,8 +35,9 @@ extra_clean = clean_ilbclib
 
 include ../Makefile.audio_module
 
-$(ILBC_DIR)/libilbc.a::
-	-@cd $(ILBC_DIR); $(MAKE) all
+$(ILBC_DIR)/libilbc.a:
+#	-@cd $(ILBC_DIR); $(MAKE) all
+	$(MAKE) -C $(ILBC_DIR) libilbc.a
 
 .PHONY: clean_ilbclib
 clean_ilbclib:
diff --git a/core/plug-in/ilbc/iLBC_rfc3951/Makefile b/core/plug-in/ilbc/iLBC_rfc3951/Makefile
index f00d59fa..818d640a 100644
--- a/core/plug-in/ilbc/iLBC_rfc3951/Makefile
+++ b/core/plug-in/ilbc/iLBC_rfc3951/Makefile
@@ -1,3 +1,5 @@
+COREPATH ?=../../..
+include $(COREPATH)/../Makefile.defs
 
 lib_name = libilbc.a
 
@@ -6,6 +8,8 @@ hrds     = $(wildcard *.h)
 objs     = $(srcs:.c=.o) 
 depends  = $(srcs:.c=.d)
 
+cflags ?= $(C_FLAGS)
+
 AR		= ar
 RANLIB		= ranlib