diff --git a/21st_century_c/Makefile b/21st_century_c/Makefile
new file mode 100644
index 0000000..81d5edf
--- /dev/null
+++ b/21st_century_c/Makefile
@@ -0,0 +1,17 @@
+CFLAGS = --std=c11 -Wall -O3
+
+
+show_tree : process_dir.h process_dir.c show_tree.c
+	$(CC) $(CFLAGS) process_dir.c $@.c -o $@
+
+simple_cplx : cplx.h complex.c simple_cplx.c
+	$(CC) `pkg-config --cflags --libs gsl` $(CFLAGS) complex.c $@.c -o $@
+
+
+.PHONY : all
+all : show_tree simple_cplx
+
+.PHONY : clean
+clean :
+	rm -f show_tree
+	rm -f simple_cplx