diff --git a/src/Makefile b/src/Makefile
index 9d326da..7176224 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -19,9 +19,9 @@ VER := $(strip $(VER))
 MY_CFLAGS = -fmessage-length=0
 
 ifeq ($(PLAT),x86)
-MY_LIBS   = -lpthread -L../lib -lrt -lscl_shm -lmodbus
+MY_LIBS   = -lpthread -L../lib -lrt -lscl_shm -lmodbus -lm
 else
-MY_LIBS   = -L../lib -lpthread -lrt -lscl_shm -lmodbus
+MY_LIBS   = -L../lib -lpthread -lrt -lscl_shm -lmodbus -lm
 endif
 
 # The pre-processor options used by the cpp (man cpp for more).
@@ -53,19 +53,19 @@ HDREXTS = .h .H .hh .hpp .HPP .h++ .hxx .hp
 # Users can override those variables from the command line.
 ifeq ($(VER),debug)
 ifeq ($(TYPE),so)
-CFLAGS  = -ggdb -pipe -O0 -fPIC -I./EasyLogger/inc -I../inc
-CXXFLAGS= -ggdb -pipe -O0 -fPIC -I./EasyLogger/inc -I../inc 
+CFLAGS  = -ggdb -pipe -O0 -fPIC -I./EasyLogger/inc -I../inc -I../inc/fft
+CXXFLAGS= -ggdb -pipe -O0 -fPIC -I./EasyLogger/inc -I../inc -I../inc/fft
 else
-CFLAGS  = -ggdb -pipe -O0 -I./EasyLogger/inc -I../inc 
-CXXFLAGS= -ggdb -pipe -O0 -I./EasyLogger/inc -I../inc
+CFLAGS  = -ggdb -pipe -O0 -I./EasyLogger/inc -I../inc -I../inc/fft
+CXXFLAGS= -ggdb -pipe -O0 -I./EasyLogger/inc -I../inc -I../inc/fft
 endif
 else
 ifeq ($(TYPE),so)
-CFLAGS  = -O2 -pipe -fPIC -I./EasyLogger/inc -I../inc
-CXXFLAGS= -O2 -pipe -fPIC -I./EasyLogger/inc -I../inc
+CFLAGS  = -O2 -pipe -fPIC -I./EasyLogger/inc -I../inc -I../inc/fft
+CXXFLAGS= -O2 -pipe -fPIC -I./EasyLogger/inc -I../inc -I../inc/fft
 else
-CFLAGS  = -O2 -pipe -I./EasyLogger/inc -I../inc
-CXXFLAGS= -O2 -pipe -I./EasyLogger/inc -I../inc
+CFLAGS  = -O2 -pipe -I./EasyLogger/inc -I../inc -I../inc/fft
+CXXFLAGS= -O2 -pipe -I./EasyLogger/inc -I../inc -I../inc/fft
 endif
 endif
 
@@ -114,8 +114,9 @@ ifeq ($(PROGRAM),)
   endif
 endif
 ifeq ($(SRCDIRS),)
-  SRCDIRS = . ./EasyLogger/src 
+  SRCDIRS = . ./EasyLogger/src ./fft
 endif
+
 SOURCES = $(foreach d,$(SRCDIRS),$(wildcard $(addprefix $(d)/*,$(SRCEXTS))))
 HEADERS = $(foreach d,$(SRCDIRS),$(wildcard $(addprefix $(d)/*,$(HDREXTS))))
 SRC_CXX = $(filter-out %.c,$(SOURCES))