diff --git a/gio/tests/modules/test-module-a.c b/gio/tests/modules/test-module-a.c
index 0644fdc3a..6ac065d8a 100644
--- a/gio/tests/modules/test-module-a.c
+++ b/gio/tests/modules/test-module-a.c
@@ -32,6 +32,8 @@ typedef struct _TestAClass {
   GObjectClass parent_class;
 } TestAClass;
 
+GType test_a_get_type (void);
+
 G_DEFINE_TYPE (TestA, test_a, G_TYPE_OBJECT)
 
 static void
diff --git a/gio/tests/modules/test-module-b.c b/gio/tests/modules/test-module-b.c
index 5ec920887..21932287f 100644
--- a/gio/tests/modules/test-module-b.c
+++ b/gio/tests/modules/test-module-b.c
@@ -32,6 +32,8 @@ typedef struct _TestBClass {
   GObjectClass parent_class;
 } TestBClass;
 
+GType test_b_get_type (void);
+
 G_DEFINE_TYPE (TestB, test_b, G_TYPE_OBJECT)
 
 static void