diff --git a/plugins/comedi/comedi.c b/plugins/comedi/comedi.c
index 71c089bbb262409be1ddfa6d4af95aac216ec71d..00a1912950c85d8711197c3f1fe91bb7406e33cc 100644
--- a/plugins/comedi/comedi.c
+++ b/plugins/comedi/comedi.c
@@ -357,7 +357,7 @@ static struct moberg_status channel_open(struct moberg_channel *channel)
     insn.n = sizeof(data) / sizeof(data[0]);
     data[0] = INSN_CONFIG_SET_ROUTING;
     data[1] = channel->context->descriptor.route;
-    if (comedi_do_insn(channel->context->device->comedi.handle, &insn)) {
+    if (0 > comedi_do_insn(channel->context->device->comedi.handle, &insn)) {
       goto err_errno;
     }
   }