diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3a8f7a2..bc91a81 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -37,6 +37,11 @@ option(
 	"use base64.ll with -DCMAKE_CXX_COMPILER=clang++"
 	OFF
 )
+option(
+	ONLY_LIB
+	"only lib"
+	OFF
+)
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
@@ -188,15 +193,17 @@ install(FILES ${MCL_HEADERS} DESTINATION include/mcl)
 install(FILES include/mcl/impl/bn_c_impl.hpp DESTINATION include/mcl/impl)
 install(FILES ${CYBOZULIB_HEADERS} DESTINATION include/cybozu)
 
-set(TEST_BASE fp_test ec_test fp_util_test window_method_test elgamal_test fp_tower_test gmp_test bn_test glv_test)
-#set(TEST_BASE bn_test)
-foreach(base IN ITEMS ${TEST_BASE})
-	add_executable(
-		${base}
-		test/${base}.cpp
-	)
-	target_link_libraries(
-		${base}
-		${LIBS}
-	)
-endforeach()
+if(NOT ONLY_LIB)
+	set(TEST_BASE fp_test ec_test fp_util_test window_method_test elgamal_test fp_tower_test gmp_test bn_test glv_test)
+	#set(TEST_BASE bn_test)
+	foreach(base IN ITEMS ${TEST_BASE})
+		add_executable(
+			${base}
+			test/${base}.cpp
+		)
+		target_link_libraries(
+			${base}
+			${LIBS}
+		)
+	endforeach()
+endif()
diff --git a/Makefile b/Makefile
index 7df1dd3..c124150 100644
--- a/Makefile
+++ b/Makefile
@@ -352,7 +352,7 @@ update_cybozulib:
 	cp -a $(addprefix ../cybozulib/,$(wildcard include/cybozu/*.hpp)) include/cybozu/
 
 clean:
-	$(RM) $(LIB_DIR)/*.a $(LIB_DIR)/*.$(LIB_SUF) $(OBJ_DIR)/*.o $(OBJ_DIR)/*.obj $(OBJ_DIR)/*.d $(EXE_DIR)/*.exe $(GEN_EXE) $(ASM_OBJ) $(LIB_OBJ) $(BN256_OBJ) $(BN384_OBJ) $(BN512_OBJ) $(LLVM_SRC) $(FUNC_LIST) src/*.ll lib/*.a
+	$(RM) $(LIB_DIR)/*.a $(LIB_DIR)/*.$(LIB_SUF) $(OBJ_DIR)/*.o $(OBJ_DIR)/*.obj $(OBJ_DIR)/*.d $(EXE_DIR)/*.exe $(GEN_EXE) $(ASM_OBJ) $(LIB_OBJ) $(BN256_OBJ) $(BN384_OBJ) $(BN512_OBJ) $(FUNC_LIST) src/*.ll lib/*.a
 
 ALL_SRC=$(SRC_SRC) $(TEST_SRC) $(SAMPLE_SRC)
 DEPEND_FILE=$(addprefix $(OBJ_DIR)/, $(addsuffix .d,$(basename $(ALL_SRC))))