diff --git a/1989/westley/Makefile b/1989/westley/Makefile
index 4c4ec0776..eef3a947a 100644
--- a/1989/westley/Makefile
+++ b/1989/westley/Makefile
@@ -140,21 +140,21 @@ alt: data ${ALT_TARGET}
 	@${TRUE}
 
 ver0: ${PROG}
-	./${PROG} < westley.c > ver0.c
+	-./${PROG} < westley.c > ver0.c
 	-${CC} ${CFLAGS} ver0.c -o $@ ${LIBS}
 
 ver1: ${PROG}
-	./${PROG} 1 < westley.c > ver1.c
+	-./${PROG} 1 < westley.c > ver1.c
 	@echo "** NOTE: this version will not compile with clang **"
 	-${CC} ${CFLAGS} ver1.c -o $@ ${LIBS}
 
 ver2: ${PROG}
-	./${PROG} 1 2 < westley.c > ver2.c
+	-./${PROG} 1 2 < westley.c > ver2.c
 	@echo "** NOTE: this version will not compile with clang **"
 	-${CC} ${CFLAGS} ver2.c -o $@ ${LIBS}
 
 ver3: ${PROG}
-	./${PROG} 1 2 3 < westley.c > ver3.c
+	-./${PROG} 1 2 3 < westley.c > ver3.c
 	@echo "** NOTE: this version will not compile with clang **"
 	-${CC} ${CFLAGS} ver3.c -o $@ ${LIBS}