diff --git a/src/ChangeLog b/src/ChangeLog
index d6e5390c84f..d976234f0c5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2011-09-30  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Port --enable-checking=all to Fedora 14 x86-64.
+	* charset.c (syms_of_charset): Also account for glibc malloc's
+	internal overhead when calculating the initial malloc maximum.
+
 	Port --enable-checking=all to Fedora 14 x86.
 	* alloc.c (XMALLOC_OVERRUN_CHECK_OVERHEAD, XMALLOC_OVERRUN_CHECK_SIZE):
 	Move to lisp.h.
diff --git a/src/charset.c b/src/charset.c
index 1209ac6b68d..f1b4897ffe6 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -2337,7 +2337,9 @@ syms_of_charset (void)
      mmap for larger allocations, and these don't work well across dumped
      systems.  */
   enum {
-    initial_malloc_max = (1 << 16) - 1 - XMALLOC_OVERRUN_CHECK_OVERHEAD,
+    glibc_malloc_overhead = 3 * sizeof (size_t) - 1,
+    initial_malloc_max =
+      (1 << 16) - 1 - glibc_malloc_overhead - XMALLOC_OVERRUN_CHECK_OVERHEAD,
     charset_table_size_init = initial_malloc_max / sizeof (struct charset)
   };