diff --git a/libguile/arrays.h b/libguile/arrays.h
index a5ce57727..9b14d4e36 100644
--- a/libguile/arrays.h
+++ b/libguile/arrays.h
@@ -59,7 +59,7 @@ typedef struct scm_i_t_array
   unsigned long base;
 } scm_i_t_array;
 
-SCM_API scm_t_bits scm_i_tc16_array;
+SCM_INTERNAL scm_t_bits scm_i_tc16_array;
 
 #define SCM_I_ARRAY_FLAG_CONTIGUOUS (1 << 0)
 
diff --git a/libguile/continuations.c b/libguile/continuations.c
index e6622612f..69a87d229 100644
--- a/libguile/continuations.c
+++ b/libguile/continuations.c
@@ -309,7 +309,7 @@ static void scm_dynthrow (SCM);
  * variable.
  */
 
-scm_t_bits scm_i_dummy;
+static scm_t_bits scm_i_dummy;
 
 static void 
 grow_stack (SCM cont)
diff --git a/libguile/discouraged.h b/libguile/discouraged.h
index 1be05f0bc..dfa5811cf 100644
--- a/libguile/discouraged.h
+++ b/libguile/discouraged.h
@@ -13,7 +13,7 @@
 #ifndef SCM_DISCOURAGED_H
 #define SCM_DISCOURAGED_H
 
-/* Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2004, 2006, 2010 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -177,7 +177,7 @@ SCM_API SCM scm_c_make_keyword (const char *s);
 #define scm_thread_sleep    scm_std_sleep
 #define scm_thread_usleep   scm_std_usleep
 
-void scm_i_init_discouraged (void);
+SCM_INTERNAL void scm_i_init_discouraged (void);
 
 #endif /* SCM_ENABLE_DISCOURAGED == 1 */
 
diff --git a/libguile/gc.c b/libguile/gc.c
index fc405f307..1e8d7ddca 100644
--- a/libguile/gc.c
+++ b/libguile/gc.c
@@ -83,12 +83,6 @@ int scm_expensive_debug_cell_accesses_p = 0;
  */
 int scm_debug_cells_gc_interval = 0;
 
-/*
-  Global variable, so you can switch it off at runtime by setting
-  scm_i_cell_validation_already_running.
- */
-int scm_i_cell_validation_already_running ;
-
 /* Hash table that keeps a reference to objects the user wants to protect from
    garbage collection.  It could arguably be private but applications have come
    to rely on it (e.g., Lilypond 2.13.9).  */
@@ -131,6 +125,9 @@ scm_i_expensive_validation_check (SCM cell)
     }
 }
 
+/* Whether cell validation is already running.  */
+static int scm_i_cell_validation_already_running = 0;
+
 void
 scm_assert_cell_valid (SCM cell)
 {
diff --git a/libguile/gc.h b/libguile/gc.h
index 3c10b8ab4..104fb0bb3 100644
--- a/libguile/gc.h
+++ b/libguile/gc.h
@@ -178,7 +178,7 @@ SCM_API SCM scm_gc_dump (void);
 SCM_API SCM scm_gc_stats (void);
 SCM_API SCM scm_gc_live_object_stats (void);
 SCM_API SCM scm_gc (void);
-SCM_API void scm_i_gc (const char *what);
+SCM_INTERNAL void scm_i_gc (const char *what);
 SCM_API void scm_gc_mark (SCM p);
 SCM_API void scm_gc_sweep (void);
 
diff --git a/libguile/numbers.c b/libguile/numbers.c
index 358a1cdf8..b1c918f0e 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
  *
  * Portions Copyright 1990, 1991, 1992, 1993 by AT&T Bell Laboratories
  * and Bellcore.  See scm_divide.
@@ -3552,7 +3552,7 @@ scm_num_eq_p (SCM x, SCM y)
    mpq_cmp.  flonum/frac compares likewise, but with the slight complication
    of the float exponent to take into account.  */
 
-SCM scm_i_num_less_p (SCM, SCM, SCM);
+SCM_INTERNAL SCM scm_i_num_less_p (SCM, SCM, SCM);
 SCM_PRIMITIVE_GENERIC (scm_i_num_less_p, "<", 0, 2, 1,
                        (SCM x, SCM y, SCM rest),
                        "Return @code{#t} if the list of parameters is monotonically\n"
diff --git a/libguile/posix.h b/libguile/posix.h
index 420311e5d..f7a5bb3a0 100644
--- a/libguile/posix.h
+++ b/libguile/posix.h
@@ -3,7 +3,7 @@
 #ifndef SCM_POSIX_H
 #define SCM_POSIX_H
 
-/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2003, 2006, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2003, 2006, 2008, 2009, 2010 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -91,7 +91,7 @@ SCM_API SCM scm_sethostname (SCM name);
 SCM_API SCM scm_gethostname (void);
 SCM_INTERNAL void scm_init_posix (void);
 
-SCM_API scm_i_pthread_mutex_t scm_i_locale_mutex;
+SCM_INTERNAL scm_i_pthread_mutex_t scm_i_locale_mutex;
 
 #endif  /* SCM_POSIX_H */