diff --git a/stagit.c b/stagit.c
@@ -708,7 +708,7 @@ writefilestree(FILE *fp, git_tree *tree, const char *branch, const char *path)
else
fprintf(fp, "%juB", (uintmax_t)filesize);
fputs("</td></tr>\n", fp);
- } else if (git_submodule_lookup(&module, repo, entryname) == 0) {
+ } else if (!git_submodule_lookup(&module, repo, entryname)) {
fputs("<tr><td>m---------</td><td>", fp);
if ((moduleurl = git_submodule_url(module))) {
fprintf(fp, "<a class=\"module\" href=\"%s\">",