diff --git a/project/common.mk b/project/common.mk
index d19f30c..40ba528 100644
--- a/project/common.mk
+++ b/project/common.mk
@@ -1,3 +1,9 @@
-COMMON_SRCS = \
+common_src_dirs   = $(PROJECT_DIR)/src/*/
+common_src_files  = $(addsuffix *.c,$(common_src_dirs))
+common_sort_files = $(sort $(wildcard $(common_src_files)))
+COMMON_SRCS       = $(subst $(PROJECT_DIR)/src/,src/,$(common_sort_files))
 
-APP_SRCS = \
+app_src_dirs      = $(PROJECT_DIR)/src/
+app_src_files     = $(addsuffix *.c,$(app_src_dirs))
+app_sort_files    = $(sort $(wildcard $(app_src_files)))
+APP_SRCS          = $(subst $(PROJECT_DIR)/src/,src/,$(app_sort_files))