diff --git a/src/main/interpreter.c b/src/main/interpreter.c
index a7507f335168..69b5499ca03f 100644
--- a/src/main/interpreter.c
+++ b/src/main/interpreter.c
@@ -1395,7 +1395,7 @@ int unlang_event_fd_readable_add(REQUEST *request, fr_unlang_fd_callback_t callb
 	ev->inst = module_instance;
 	ev->ctx = ctx;
 
-	if (fr_event_fd_insert(request->el, fd, unlang_event_fd_handler, NULL, NULL, ev) < 0) {
+	if (!fr_event_fd_insert(request->el, fd, unlang_event_fd_handler, NULL, NULL, ev)) {
 		talloc_free(ev);
 		return -1;
 	}
diff --git a/src/main/process.c b/src/main/process.c
index 11de5b4b71a1..97fbd344406e 100644
--- a/src/main/process.c
+++ b/src/main/process.c
@@ -4886,7 +4886,7 @@ static int event_new_fd(rad_listen_t *this)
 		/*
 		 *	All sockets: add the FD to the event handler.
 		 */
-		if (fr_event_fd_insert(el, this->fd, event_socket_handler, NULL, NULL, this) < 0) {
+		if (!fr_event_fd_insert(el, this->fd, event_socket_handler, NULL, NULL, this)) {
 			ERROR("Failed adding event handler for socket: %s", fr_strerror());
 			fr_exit(1);
 		}
@@ -5391,7 +5391,7 @@ int radius_event_start(bool have_children)
 	}
 	DEBUG4("Created signal pipe.  Read end FD %i, write end FD %i", self_pipe[0], self_pipe[1]);
 
-	if (fr_event_fd_insert(el, self_pipe[0], event_signal_handler, NULL, NULL, el) < 0) {
+	if (!fr_event_fd_insert(el, self_pipe[0], event_signal_handler, NULL, NULL, el)) {
 		ERROR("Failed creating signal pipe handler: %s", fr_strerror());
 		return -1;
 	}
diff --git a/src/main/radsniff.c b/src/main/radsniff.c
index 11e2d690bf16..1af4f82861b8 100644
--- a/src/main/radsniff.c
+++ b/src/main/radsniff.c
@@ -2800,7 +2800,7 @@ int main(int argc, char *argv[])
 			exit(EXIT_FAILURE);
 		}
 
-		if (fr_event_fd_insert(events, self_pipe[0], rs_signal_action, NULL, NULL, events) < 0) {
+		if (!fr_event_fd_insert(events, self_pipe[0], rs_signal_action, NULL, NULL, events)) {
 			ERROR("Failed inserting signal pipe descriptor: %s", fr_strerror());
 			goto finish;
 		}
@@ -2819,7 +2819,7 @@ int main(int argc, char *argv[])
 			event->out = out;
 			event->stats = stats;
 
-			if (fr_event_fd_insert(events, in_p->fd, rs_got_packet, NULL, NULL, event) < 0) {
+			if (!fr_event_fd_insert(events, in_p->fd, rs_got_packet, NULL, NULL, event)) {
 				ERROR("Failed inserting file descriptor");
 				goto finish;
 			}
diff --git a/src/main/threads.c b/src/main/threads.c
index 13e4f4d10da8..b3f7fc65006c 100644
--- a/src/main/threads.c
+++ b/src/main/threads.c
@@ -461,7 +461,7 @@ static void *thread_handler(void *arg)
 	local_backlog = fr_heap_create(timestamp_cmp, offsetof(REQUEST, heap_id));
 	rad_assert(local_backlog != NULL);
 
-	if (fr_event_fd_insert(el, thread->pipe_fd[0], thread_fd_handler, NULL, NULL, thread) < 0) {
+	if (!fr_event_fd_insert(el, thread->pipe_fd[0], thread_fd_handler, NULL, NULL, thread)) {
 		ERROR("Failed inserting event for self");
 		goto done;
 	}
diff --git a/src/modules/proto_bfd/proto_bfd.c b/src/modules/proto_bfd/proto_bfd.c
index 3d9d08538fb2..fc4c151d46a5 100644
--- a/src/modules/proto_bfd/proto_bfd.c
+++ b/src/modules/proto_bfd/proto_bfd.c
@@ -332,7 +332,7 @@ static int bfd_pthread_create(bfd_state_t *session)
 	fcntl(session->pipefd[1], F_SETFL, O_NONBLOCK | FD_CLOEXEC);
 #endif
 
-	if (fr_event_fd_insert(session->el, session->pipefd[0], bfd_pipe_recv, NULL, NULL, session) < 0) {
+	if (!fr_event_fd_insert(session->el, session->pipefd[0], bfd_pipe_recv, NULL, NULL, session)) {
 		ERROR("Failed inserting file descriptor into event list: %s", fr_strerror());
 		goto close_pipes;
 	}
diff --git a/src/modules/rlm_radius_client/rlm_radius_client.c b/src/modules/rlm_radius_client/rlm_radius_client.c
index 6c1cb2f88a4e..32d6791405a9 100644
--- a/src/modules/rlm_radius_client/rlm_radius_client.c
+++ b/src/modules/rlm_radius_client/rlm_radius_client.c
@@ -367,7 +367,7 @@ static int mod_fd_add(fr_event_list_t *el, rlm_radius_client_conn_t *conn, rlm_r
 		return -1;
 	}
 
-	if (fr_event_fd_insert(el, sockfd, mod_event_fd, NULL, NULL, conn) < 0) {
+	if (!fr_event_fd_insert(el, sockfd, mod_event_fd, NULL, NULL, conn)) {
 		DEBUG("Failed adding event for socket: %s", fr_strerror());
 		close(sockfd);
 		return -1;
diff --git a/src/modules/rlm_unbound/rlm_unbound.c b/src/modules/rlm_unbound/rlm_unbound.c
index c121593fad2e..92d41800aa55 100644
--- a/src/modules/rlm_unbound/rlm_unbound.c
+++ b/src/modules/rlm_unbound/rlm_unbound.c
@@ -625,7 +625,7 @@ static int mod_instantiate(CONF_SECTION *conf, void *instance)
 
 	inst->log_fd = ub_fd(inst->ub);
 	if (inst->log_fd >= 0) {
-		if (fr_event_fd_insert(inst->el, inst->log_fd, ub_fd_handler, NULL, NULL, inst) < 0) {
+		if (!fr_event_fd_insert(inst->el, inst->log_fd, ub_fd_handler, NULL, NULL, inst)) {
 			cf_log_err_cs(conf, "could not insert async fd");
 			inst->log_fd = -1;
 			goto error_nores;