diff --git a/src/gui/event-editor/gcal-schedule-section.c b/src/gui/event-editor/gcal-schedule-section.c
index 5cac4615..df13904d 100644
--- a/src/gui/event-editor/gcal-schedule-section.c
+++ b/src/gui/event-editor/gcal-schedule-section.c
@@ -949,3 +949,9 @@ gcal_schedule_values_free (GcalScheduleValues *values)
 
   g_free (values);
 }
+
+void
+gcal_schedule_section_add_tests (void)
+{
+  /* g_test_add_func ("/event_editor/schedule_section/...", ...); */
+}
diff --git a/src/gui/event-editor/gcal-schedule-section.h b/src/gui/event-editor/gcal-schedule-section.h
index 04211c12..35ec0a46 100644
--- a/src/gui/event-editor/gcal-schedule-section.h
+++ b/src/gui/event-editor/gcal-schedule-section.h
@@ -23,6 +23,10 @@
 #include <adwaita.h>
 #include <gtk/gtk.h>
 
+#include "gcal-enums.h"
+#include "gcal-event.h"
+#include "gcal-recurrence.h"
+
 G_BEGIN_DECLS
 
 #define GCAL_TYPE_SCHEDULE_SECTION (gcal_schedule_section_get_type())
@@ -52,4 +56,8 @@ void                 gcal_schedule_values_free                   (GcalScheduleVa
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (GcalScheduleValues, gcal_schedule_values_free);
 
+/* Tests */
+
+void gcal_schedule_section_add_tests (void);
+
 G_END_DECLS
diff --git a/src/gui/gcal-tests.c b/src/gui/gcal-tests.c
new file mode 100644
index 00000000..979ba9fc
--- /dev/null
+++ b/src/gui/gcal-tests.c
@@ -0,0 +1,15 @@
+#include <glib.h>
+
+#include "gcal-tests.h"
+#include "event-editor/gcal-schedule-section.h"
+
+/* Adds all the tests for the internals of the GUI.
+ *
+ * To avoid exporting lots of little test functions from each source file, add a single
+ * gcal_foo_add_tests() that in turn adds unit tests for that file.
+ */
+void
+gcal_tests_add_internals (void)
+{
+  gcal_schedule_section_add_tests ();
+}
diff --git a/src/gui/gcal-tests.h b/src/gui/gcal-tests.h
new file mode 100644
index 00000000..346d13fc
--- /dev/null
+++ b/src/gui/gcal-tests.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void gcal_tests_add_internals (void);
diff --git a/src/gui/meson.build b/src/gui/meson.build
index 7fbebd2c..aff98194 100644
--- a/src/gui/meson.build
+++ b/src/gui/meson.build
@@ -52,6 +52,7 @@ sources += files(
   'gcal-quick-add-popover.c',
   'gcal-search-button.c',
   'gcal-sync-indicator.c',
+  'gcal-tests.c',
   'gcal-weather-settings.c',
   'gcal-window.c',
 )
diff --git a/tests/meson.build b/tests/meson.build
index 29aff0a2..682fff56 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -35,6 +35,7 @@ tests = [
   'daylight-saving',
   #'discoverer', # https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/1251
   'event',
+  'internals',
   'range',
   'range-tree',
   #'server', # https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/1251
diff --git a/tests/test-internals.c b/tests/test-internals.c
new file mode 100644
index 00000000..239e569c
--- /dev/null
+++ b/tests/test-internals.c
@@ -0,0 +1,17 @@
+#include <glib.h>
+#include <locale.h>
+
+#include "gui/gcal-tests.h"
+
+int
+main (int argc, char **argv)
+{
+  g_setenv ("TZ", "UTC", TRUE);
+
+  g_test_init (&argc, &argv, NULL);
+  g_test_bug_base ("https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/");
+
+  gcal_tests_add_internals ();
+
+  return g_test_run ();
+}