diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c
index 30207c048d36..c6bb1e72e0f1 100644
--- a/kernel/bpf/preload/bpf_preload_kern.c
+++ b/kernel/bpf/preload/bpf_preload_kern.c
@@ -54,6 +54,7 @@ static int load_skel(void)
 		err = PTR_ERR(progs_link);
 		goto out;
 	}
+	iterators_bpf__detach(skel);
 	return 0;
 out:
 	free_links_and_skel();
diff --git a/kernel/bpf/preload/iterators/iterators.lskel.h b/kernel/bpf/preload/iterators/iterators.lskel.h
index 70f236a82fe1..25294fd88f10 100644
--- a/kernel/bpf/preload/iterators/iterators.lskel.h
+++ b/kernel/bpf/preload/iterators/iterators.lskel.h
@@ -28,7 +28,7 @@ iterators_bpf__dump_bpf_map__attach(struct iterators_bpf *skel)
 	int prog_fd = skel->progs.dump_bpf_map.prog_fd;
 	int fd = skel_link_create(prog_fd, 0, BPF_TRACE_ITER);
 
-	if (fd > 0)
+	if (fd >= 0)
 		skel->links.dump_bpf_map_fd = fd;
 	return fd;
 }
@@ -39,7 +39,7 @@ iterators_bpf__dump_bpf_prog__attach(struct iterators_bpf *skel)
 	int prog_fd = skel->progs.dump_bpf_prog.prog_fd;
 	int fd = skel_link_create(prog_fd, 0, BPF_TRACE_ITER);
 
-	if (fd > 0)
+	if (fd >= 0)
 		skel->links.dump_bpf_prog_fd = fd;
 	return fd;
 }
@@ -57,8 +57,10 @@ iterators_bpf__attach(struct iterators_bpf *skel)
 static inline void
 iterators_bpf__detach(struct iterators_bpf *skel)
 {
-	skel_closenz(skel->links.dump_bpf_map_fd);
-	skel_closenz(skel->links.dump_bpf_prog_fd);
+	skel_closenez(skel->links.dump_bpf_map_fd);
+	skel->links.dump_bpf_map_fd = -1;
+	skel_closenez(skel->links.dump_bpf_prog_fd);
+	skel->links.dump_bpf_prog_fd = -1;
 }
 static void
 iterators_bpf__destroy(struct iterators_bpf *skel)
@@ -66,10 +68,10 @@ iterators_bpf__destroy(struct iterators_bpf *skel)
 	if (!skel)
 		return;
 	iterators_bpf__detach(skel);
-	skel_closenz(skel->progs.dump_bpf_map.prog_fd);
-	skel_closenz(skel->progs.dump_bpf_prog.prog_fd);
+	skel_closenez(skel->progs.dump_bpf_map.prog_fd);
+	skel_closenez(skel->progs.dump_bpf_prog.prog_fd);
 	skel_free_map_data(skel->rodata, skel->maps.rodata.initial_value, 4096);
-	skel_closenz(skel->maps.rodata.map_fd);
+	skel_closenez(skel->maps.rodata.map_fd);
 	skel_free(skel);
 }
 static inline struct iterators_bpf *
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 145734b4fe41..e60b3feeddef 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -469,7 +469,7 @@ static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name)
 		codegen("\
 			\n\
 										    \n\
-				if (fd > 0)					    \n\
+				if (fd >= 0)					    \n\
 					skel->links.%1$s_fd = fd;		    \n\
 				return fd;					    \n\
 			}							    \n\
@@ -506,7 +506,8 @@ static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name)
 	bpf_object__for_each_program(prog, obj) {
 		codegen("\
 			\n\
-				skel_closenz(skel->links.%1$s_fd);	    \n\
+				skel_closenez(skel->links.%1$s_fd);	    \n\
+				skel->links.%1$s_fd = -1;	    \n\
 			", bpf_program__name(prog));
 	}
 
@@ -536,7 +537,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name)
 	bpf_object__for_each_program(prog, obj) {
 		codegen("\
 			\n\
-				skel_closenz(skel->progs.%1$s.prog_fd);	    \n\
+				skel_closenez(skel->progs.%1$s.prog_fd);	    \n\
 			", bpf_program__name(prog));
 	}
 
@@ -549,7 +550,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name)
 			       ident, bpf_map_mmap_sz(map));
 		codegen("\
 			\n\
-				skel_closenz(skel->maps.%1$s.map_fd);	    \n\
+				skel_closenez(skel->maps.%1$s.map_fd);	    \n\
 			", ident);
 	}
 	codegen("\
diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index bd6f4505e7b1..51e81e79bdf2 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -204,11 +204,11 @@ static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz, int
 }
 #endif
 
-static inline int skel_closenz(int fd)
+static inline int skel_closenez(int fd)
 {
-	if (fd > 0)
-		return close(fd);
-	return -EINVAL;
+	if (fd < 0)
+		return -EINVAL;
+	return close(fd);
 }
 
 #ifndef offsetofend
