diff --git a/ui-blame.c b/ui-blame.c
index 644c30a..f28eea0 100644
--- a/ui-blame.c
+++ b/ui-blame.c
@@ -290,8 +290,10 @@ void cgit_print_blame(void)
 	walk_tree_ctx.match_baselen = (path_items.match) ?
 				       basedir_len(path_items.match) : -1;
 
-	read_tree_recursive(the_repository, commit->maybe_tree, "", 0, 0,
-		&paths, walk_tree, &walk_tree_ctx);
+	read_tree_recursive(the_repository,
+			    repo_get_commit_tree(the_repository, commit),
+			    "", 0, 0,
+			    &paths, walk_tree, &walk_tree_ctx);
 	if (!walk_tree_ctx.state)
 		cgit_print_error_page(404, "Not found", "Not found");
 	else if (walk_tree_ctx.state == 2)
diff --git a/ui-blob.c b/ui-blob.c
index 30e2d4b..f76c641 100644
--- a/ui-blob.c
+++ b/ui-blob.c
@@ -56,8 +56,9 @@ int cgit_ref_path_exists(const char *path, const char *ref, int file_only)
 		goto done;
 	if (oid_object_info(the_repository, &oid, &size) != OBJ_COMMIT)
 		goto done;
-	read_tree_recursive(the_repository, lookup_commit_reference(the_repository, &oid)->maybe_tree,
-		"", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+	read_tree_recursive(the_repository,
+			    repo_get_commit_tree(the_repository, lookup_commit_reference(the_repository, &oid)),
+			    "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
 
 done:
 	free(path_items.match);
@@ -91,8 +92,10 @@ int cgit_print_file(char *path, const char *head, int file_only)
 	type = oid_object_info(the_repository, &oid, &size);
 	if (type == OBJ_COMMIT) {
 		commit = lookup_commit_reference(the_repository, &oid);
-		read_tree_recursive(the_repository, commit->maybe_tree,
-			"", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+		read_tree_recursive(the_repository,
+				    repo_get_commit_tree(the_repository, commit),
+				    "", 0, 0, &paths, walk_tree,
+				    &walk_tree_ctx);
 		if (!walk_tree_ctx.found_path)
 			return -1;
 		type = oid_object_info(the_repository, &oid, &size);
@@ -148,8 +151,10 @@ void cgit_print_blob(const char *hex, char *path, const char *head, int file_onl
 
 	if ((!hex) && type == OBJ_COMMIT && path) {
 		commit = lookup_commit_reference(the_repository, &oid);
-		read_tree_recursive(the_repository, commit->maybe_tree,
-			"", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+		read_tree_recursive(the_repository,
+				    repo_get_commit_tree(the_repository, commit),
+				    "", 0, 0, &paths, walk_tree,
+				    &walk_tree_ctx);
 		type = oid_object_info(the_repository, &oid, &size);
 	}
 
diff --git a/ui-commit.c b/ui-commit.c
index 9a47b54..783211f 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -78,7 +78,7 @@ void cgit_print_commit(char *hex, const char *prefix)
 	html(")</td></tr>\n");
 	html("<tr><th>tree</th><td colspan='2' class='sha1'>");
 	tmp = xstrdup(hex);
-	cgit_tree_link(oid_to_hex(&commit->maybe_tree->object.oid), NULL, NULL,
+	cgit_tree_link(oid_to_hex(get_commit_tree_oid(commit)), NULL, NULL,
 		       ctx.qry.head, tmp, NULL);
 	if (prefix) {
 		html(" /");
diff --git a/ui-diff.c b/ui-diff.c
index c60aefd..329c350 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -413,7 +413,7 @@ void cgit_print_diff(const char *new_rev, const char *old_rev,
 			"Bad commit: %s", oid_to_hex(new_rev_oid));
 		return;
 	}
-	new_tree_oid = &commit->maybe_tree->object.oid;
+	new_tree_oid = get_commit_tree_oid(commit);
 
 	if (old_rev) {
 		if (get_oid(old_rev, old_rev_oid)) {
@@ -434,7 +434,7 @@ void cgit_print_diff(const char *new_rev, const char *old_rev,
 				"Bad commit: %s", oid_to_hex(old_rev_oid));
 			return;
 		}
-		old_tree_oid = &commit2->maybe_tree->object.oid;
+		old_tree_oid = get_commit_tree_oid(commit2);
 	} else {
 		old_tree_oid = NULL;
 	}
diff --git a/ui-log.c b/ui-log.c
index dc5cb1e..2939c01 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -153,8 +153,8 @@ static int show_commit(struct commit *commit, struct rev_info *revs)
 	rem_lines = 0;
 
 	revs->diffopt.flags.recursive = 1;
-	diff_tree_oid(&parent->maybe_tree->object.oid,
-		      &commit->maybe_tree->object.oid,
+	diff_tree_oid(get_commit_tree_oid(parent),
+		      get_commit_tree_oid(commit),
 		      "", &revs->diffopt);
 	diffcore_std(&revs->diffopt);
 
diff --git a/ui-plain.c b/ui-plain.c
index b73c1cf..2a7b18c 100644
--- a/ui-plain.c
+++ b/ui-plain.c
@@ -193,13 +193,14 @@ void cgit_print_plain(void)
 	if (!path_items.match) {
 		path_items.match = "";
 		walk_tree_ctx.match_baselen = -1;
-		print_dir(&commit->maybe_tree->object.oid, "", 0, "");
+		print_dir(get_commit_tree_oid(commit), "", 0, "");
 		walk_tree_ctx.match = 2;
 	}
 	else
 		walk_tree_ctx.match_baselen = basedir_len(path_items.match);
-	read_tree_recursive(the_repository, commit->maybe_tree,
-		"", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+	read_tree_recursive(the_repository,
+		            repo_get_commit_tree(the_repository, commit),
+		            "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
 	if (!walk_tree_ctx.match)
 		cgit_print_error_page(404, "Not found", "Not found");
 	else if (walk_tree_ctx.match == 2)
diff --git a/ui-tree.c b/ui-tree.c
index 84eb17d..1e4efb2 100644
--- a/ui-tree.c
+++ b/ui-tree.c
@@ -370,12 +370,14 @@ void cgit_print_tree(const char *rev, char *path)
 	walk_tree_ctx.curr_rev = xstrdup(rev);
 
 	if (path == NULL) {
-		ls_tree(&commit->maybe_tree->object.oid, NULL, &walk_tree_ctx);
+		ls_tree(get_commit_tree_oid(commit), NULL, &walk_tree_ctx);
 		goto cleanup;
 	}
 
-	read_tree_recursive(the_repository, commit->maybe_tree, "", 0, 0,
-		&paths, walk_tree, &walk_tree_ctx);
+	read_tree_recursive(the_repository,
+			    repo_get_commit_tree(the_repository, commit),
+			    "", 0, 0,
+			    &paths, walk_tree, &walk_tree_ctx);
 	if (walk_tree_ctx.state == 1)
 		ls_tail();
 	else if (walk_tree_ctx.state == 2)