diff --git a/src/libbpf.c b/src/libbpf.c
index 613afae..f7a0517 100644
--- a/src/libbpf.c
+++ b/src/libbpf.c
@@ -9966,9 +9966,9 @@ const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_siz
 
 int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size)
 {
-	if (log_size && !log_buf)
+	if (!!log_buf != !!log_size)
 		return libbpf_err(-EINVAL);
-	if (prog->log_size > UINT_MAX)
+	if (log_size > UINT_MAX)
 		return libbpf_err(-EINVAL);
 	if (prog->obj->state >= OBJ_LOADED)
 		return libbpf_err(-EBUSY);