diff --git a/epan/prefs.c b/epan/prefs.c
index 7d1ac2ae5a..5e0b8e6268 100644
--- a/epan/prefs.c
+++ b/epan/prefs.c
@@ -455,7 +455,7 @@ prefs_deregister_module(module_t *parent, const char *name, const char *title)
  * at the top level and the title used in the tab for it in a preferences
  * dialog box.
  */
-module_t *
+static module_t *
 prefs_register_subtree(module_t *parent, const char *title, const char *description,
                        void (*apply_cb)(void))
 {
diff --git a/epan/prefs.h b/epan/prefs.h
index cd88dac9b4..4a8566c63f 100644
--- a/epan/prefs.h
+++ b/epan/prefs.h
@@ -269,15 +269,6 @@ WS_DLL_PUBLIC void prefs_reset(void);
 /** Frees memory used by proto routines. Called at program shutdown */
 void prefs_cleanup(void);
 
-/*
- * Register a subtree that will have modules under it.
- * Specify the module under which to register it or NULL to register it
- * at the top level and the title used in the tab for it in a preferences
- * dialog box.
- */
-WS_DLL_PUBLIC module_t *prefs_register_subtree(module_t *parent, const char *title,
-    const char *description, void (*apply_cb)(void));
-
 /*
  * Register that a protocol has preferences.
  */