diff --git a/CHANGELOG b/CHANGELOG
index abddb649..57e54a0b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -116,6 +116,9 @@ HISTORY
 
   ++ Bugfixes:
 
+  2009-07-28 Simon Goldschmidt
+  * mem.h: Fixed bug #27105: "realloc() cannot replace mem_realloc()"s
+
   2009-07-27 Kieran Mansley
   * api.h api_msg.h netdb.h sockets.h: add missing #include directives
 
diff --git a/src/include/lwip/mem.h b/src/include/lwip/mem.h
index ff9521f3..327c2049 100644
--- a/src/include/lwip/mem.h
+++ b/src/include/lwip/mem.h
@@ -59,7 +59,11 @@ typedef size_t mem_size_t;
 #define mem_calloc calloc
 #endif
 #ifndef mem_realloc
-#define mem_realloc realloc
+static void *mem_realloc(void *mem, mem_size_t size)
+{
+  LWIP_UNUSED_ARG(size);
+  return mem;
+}
 #endif
 #else /* MEM_LIBC_MALLOC */