diff --git a/src/cmd/5l/obj.c b/src/cmd/5l/obj.c
index 202c2e80046..7c9cb1ae24d 100644
--- a/src/cmd/5l/obj.c
+++ b/src/cmd/5l/obj.c
@@ -252,6 +252,7 @@ main(int argc, char *argv[])
 	dtype = 4;
 	if(outfile == 0)
 		outfile = "5.out";
+	unlink(outfile);
 	cout = create(outfile, 1, 0775);
 	if(cout < 0) {
 		diag("%s: cannot create", outfile);
diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 66d1e7eedec..75fe3ca0313 100644
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -337,6 +337,7 @@ main(int argc, char *argv[])
 	edatap = P;
 	pc = 0;
 	dtype = 4;
+	unlink(outfile);
 	cout = create(outfile, 1, 0775);
 	if(cout < 0) {
 		diag("cannot create %s", outfile);
diff --git a/src/cmd/8l/obj.c b/src/cmd/8l/obj.c
index 5d230939d15..ce57521b7e3 100644
--- a/src/cmd/8l/obj.c
+++ b/src/cmd/8l/obj.c
@@ -306,6 +306,7 @@ main(int argc, char *argv[])
 	edatap = P;
 	pc = 0;
 	dtype = 4;
+	unlink(outfile);
 	cout = create(outfile, 1, 0775);
 	if(cout < 0) {
 		diag("cannot create %s", outfile);