diff --git a/dlls/api-ms-win-crt-heap-l1-1-0/api-ms-win-crt-heap-l1-1-0.spec b/dlls/api-ms-win-crt-heap-l1-1-0/api-ms-win-crt-heap-l1-1-0.spec
index 418926efbae..0a99e870be2 100644
--- a/dlls/api-ms-win-crt-heap-l1-1-0/api-ms-win-crt-heap-l1-1-0.spec
+++ b/dlls/api-ms-win-crt-heap-l1-1-0/api-ms-win-crt-heap-l1-1-0.spec
@@ -18,7 +18,7 @@
 @ cdecl _msize(ptr) ucrtbase._msize
 @ stub _query_new_handler
 @ stub _query_new_mode
-@ stub _realloc_base
+@ cdecl _realloc_base(ptr long) ucrtbase._realloc_base
 @ cdecl _recalloc(ptr long long) ucrtbase._recalloc
 @ cdecl _set_new_mode(long) ucrtbase._set_new_mode
 @ cdecl calloc(long long) ucrtbase.calloc
diff --git a/dlls/msvcrt/heap.c b/dlls/msvcrt/heap.c
index 8a84802c842..3ae25990b41 100644
--- a/dlls/msvcrt/heap.c
+++ b/dlls/msvcrt/heap.c
@@ -459,6 +459,14 @@ void* CDECL MSVCRT_realloc(void* ptr, MSVCRT_size_t size)
   return NULL;
 }
 
+/*********************************************************************
+ *		_realloc_base (UCRTBASE.@)
+ */
+void* CDECL _realloc_base(void* ptr, MSVCRT_size_t size)
+{
+  return MSVCRT_realloc(ptr, size);
+}
+
 /*********************************************************************
  * _recalloc (MSVCR100.@)
  */
diff --git a/dlls/ucrtbase/ucrtbase.spec b/dlls/ucrtbase/ucrtbase.spec
index ff21fb30b85..64f62764b58 100644
--- a/dlls/ucrtbase/ucrtbase.spec
+++ b/dlls/ucrtbase/ucrtbase.spec
@@ -1859,7 +1859,7 @@
 @ stub _query_new_handler
 @ stub _query_new_mode
 @ cdecl _read(long ptr long) MSVCRT__read
-@ stub _realloc_base
+@ cdecl _realloc_base(ptr long)
 @ cdecl _recalloc(ptr long long)
 @ cdecl _register_onexit_function(ptr ptr) MSVCRT__register_onexit_function
 @ stub _register_thread_local_exe_atexit_callback