diff --git a/src/WINNT/client_creds/afscreds.h b/src/WINNT/client_creds/afscreds.h
index 14e51a8c7e..422c8385c7 100644
--- a/src/WINNT/client_creds/afscreds.h
+++ b/src/WINNT/client_creds/afscreds.h
@@ -17,6 +17,7 @@
  */
 
 #include <WINNT/TaLocale.h>
+#undef REALLOC /* RT ticket 2120; So we can redefine it later */
 #include <windows.h>
 #include <commctrl.h>
 #include <regstr.h>