diff --git a/docs/reference/gdk/meson.build b/docs/reference/gdk/meson.build
index 3dc7a0ff92..d5429928e1 100644
--- a/docs/reference/gdk/meson.build
+++ b/docs/reference/gdk/meson.build
@@ -13,6 +13,7 @@ if get_option('gtk_doc')
       gidocgen,
       'generate',
       '--quiet',
+      '--fatal-warnings',
       '--add-include-path=@0@'.format(meson.current_build_dir() / '../../../gtk'),
       '--config=@INPUT0@',
       '--output-dir=@OUTPUT@',
@@ -34,6 +35,7 @@ if get_option('gtk_doc')
         gidocgen,
         'generate',
         '--quiet',
+        '--fatal-warnings',
         '--add-include-path=@0@'.format(meson.current_build_dir() / '../../../gtk'),
         '--config=@INPUT0@',
         '--output-dir=@OUTPUT@',
@@ -57,6 +59,7 @@ if get_option('gtk_doc')
         gidocgen,
         'generate',
         '--quiet',
+        '--fatal-warnings',
         '--add-include-path=@0@'.format(meson.current_build_dir() / '../../../gtk'),
         '--config=@INPUT0@',
         '--output-dir=@OUTPUT@',
diff --git a/docs/reference/gsk/meson.build b/docs/reference/gsk/meson.build
index f482f9fd6f..db80a68898 100644
--- a/docs/reference/gsk/meson.build
+++ b/docs/reference/gsk/meson.build
@@ -8,6 +8,7 @@ if get_option('gtk_doc')
       gidocgen,
       'generate',
       '--quiet',
+      '--fatal-warnings',
       '--add-include-path=@0@'.format(meson.current_build_dir() / '../../../gtk'),
       '--config=@INPUT0@',
       '--output-dir=@OUTPUT@',
diff --git a/docs/reference/gtk/meson.build b/docs/reference/gtk/meson.build
index 7452b39f4c..0d785b26de 100644
--- a/docs/reference/gtk/meson.build
+++ b/docs/reference/gtk/meson.build
@@ -37,6 +37,7 @@ if get_option('gtk_doc')
       gidocgen,
       'generate',
       '--quiet',
+      '--fatal-warnings',
       '--add-include-path=@0@'.format(meson.current_build_dir() / '../../../gtk'),
       '--config=@INPUT0@',
       '--output-dir=@OUTPUT@',