--- Makefile.orig	2020-09-23 11:00:09 UTC
+++ Makefile
@@ -11,7 +11,7 @@
 #	On GNU,		        use S_CHAR="char"
 #
 
-CFLAGS+=	-DF77 -DS_CHAR="char"
+CFLAGS+=	-DF77 -DS_CHAR="char" -Wno-error=return-type
 #CFLAGS+=	-DS_CHAR="char"
 OBJS=		rat4.o lookup.o getopt.o
 
@@ -26,13 +26,18 @@ ratfor: ratfor77
 clean:
 	rm -f *.o *~ ratfor ratfor77 a.out test testw test.f testw.f
 
-test: ratfor
+.f:
+	${FC} -o $@ $<
+
+test: test.f
+
+test.f: ratfor
 	./ratfor -o test.f test.r
-	f77 -o test test.f
 
-testw: ratfor
+testw: testw.f
+
+testw.f: ratfor
 	./ratfor -o testw.f testw.r
-	f77 -o testw testw.f
 
 tests: test testw
 	./test