diff --git a/CMakeLists.txt b/CMakeLists.txt
index 796c292a..7de6956a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.8)
+cmake_minimum_required(VERSION 2.8)
 
 PROJECT(picrin)
 
@@ -18,9 +18,6 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY lib)
 set(CMAKE_C_FLAGS "-Wall -Wextra -std=c99")
 set(CMAKE_C_FLAGS_DEBUG "-g -DDEBUG=1")
 
-# external libraries
-add_library(xfile OBJECT extlib/xfile/xfile.c)
-
 # build picrin
 include_directories(include extlib)
 include(src/CMakeLists.txt)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index cbecb0a8..6a9705c0 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,7 +3,10 @@ find_package(FLEX REQUIRED)
 flex_target(scan src/scan.l ${PROJECT_SOURCE_DIR}/src/lex.yy.c COMPILE_FLAGS --header-file="src/lex.yy.h")
 set_directory_properties(PROPERTIES ADDITIONAL_MAKE_CLEAN_FILES ${PROJECT_SOURCE_DIR}/src/lex.yy.h)
 
+# xfile
+set(XFILE_SOURCES extlib/xfile/xfile.c)
+
 # build!
 file(GLOB C_SOURCES ${PROJECT_SOURCE_DIR}/src/*.c)
-add_library(picrin SHARED ${C_SOURCES} ${FLEX_scan_OUTPUTS} $<TARGET_OBJECTS:xfile>)
+add_library(picrin SHARED ${C_SOURCES} ${FLEX_scan_OUTPUTS} ${XFILE_SOURCES})
 target_link_libraries(picrin m)