diff --git a/src/odoc/compile.ml b/src/odoc/compile.ml
index b1581f3d44..d3d2000ecb 100644
--- a/src/odoc/compile.ml
+++ b/src/odoc/compile.ml
@@ -249,8 +249,7 @@ let mld ~parent_id ~parents_children ~output ~children ~warnings_options input =
     let zero_heading = Comment.find_zero_heading content in
     if (not (is_index_page name)) && has_children_order frontmatter then
       Error.raise_warning
-        (Error.filename_only
-           "Non-index page cannot specify (children _) in the frontmatter."
+        (Error.filename_only "Non-index page cannot specify @children_order."
            input_s);
     let root =
       let file =
diff --git a/test/frontmatter/frontmatter.t/run.t b/test/frontmatter/frontmatter.t/run.t
index 8b17511e9a..4bdb9baac7 100644
--- a/test/frontmatter/frontmatter.t/run.t
+++ b/test/frontmatter/frontmatter.t/run.t
@@ -10,7 +10,7 @@ When there is one frontmatter, it is extracted from the content:
 
   $ odoc compile one_frontmatter.mld
   File "one_frontmatter.mld":
-  Warning: Non-index page cannot specify (children _) in the frontmatter.
+  Warning: Non-index page cannot specify @children_order.
   $ odoc_print page-one_frontmatter.odoc | jq '.frontmatter'
   {
     "children": {
@@ -62,7 +62,7 @@ When there is more than one children order, we raise a warning and keep only the
   File "two_frontmatters.mld", line 2, characters 0-25:
   Warning: Duplicated @children_order entry
   File "two_frontmatters.mld":
-  Warning: Non-index page cannot specify (children _) in the frontmatter.
+  Warning: Non-index page cannot specify @children_order.
   $ odoc_print page-two_frontmatters.odoc | jq '.frontmatter'
   {
     "children": {
diff --git a/test/frontmatter/toc_order.t/run.t b/test/frontmatter/toc_order.t/run.t
index 16a65f3583..754cdd0257 100644
--- a/test/frontmatter/toc_order.t/run.t
+++ b/test/frontmatter/toc_order.t/run.t
@@ -105,4 +105,4 @@ Some more parsing test:
   > EOF
   $ odoc compile --parent-id pkg/doc --output-dir _odoc errors/not_index.mld
   File "errors/not_index.mld":
-  Warning: Non-index page cannot specify (children _) in the frontmatter.
+  Warning: Non-index page cannot specify @children_order.