diff --git a/sk2/Makefile b/sk2/Makefile
index b564c50..776d7de 100644
--- a/sk2/Makefile
+++ b/sk2/Makefile
@@ -1,17 +1,17 @@
 CC=gcc
-CFLAGS=-Wall -Wextra -std=c11
+CFLAGS=-Wall -Wextra -std=c11 -MMD -MP
 OBJ=main.o calculator.o
+DEP=$(OBJ:.o=.d)
 
 all: calculator
 
 calculator: $(OBJ)
-	$(CC) $(CFLAGS) -o calculator $(OBJ) -lm
+	$(CC) $(CFLAGS) -o $@ $^ -lm
 
-main.o: main.c calculator.h
-	$(CC) $(CFLAGS) -c main.c
-
-calculator.o: calculator.c calculator.h
-	$(CC) $(CFLAGS) -c calculator.c
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
 
 clean:
-	rm -f calculator $(OBJ)
+	rm -f calculator $(OBJ) $(DEP)
+
+-include $(DEP)