diff --git a/acconfig.h b/acconfig.h
index 4a2156c3cf..5af06e90a5 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -13,6 +13,11 @@
 
 /* end of preamble */
 
+#if !defined(SLAPD_SCHEMA_COMPAT) && !defined(SLAPD_SCHEMA_NOT_COMPAT)
+	/* define SLAPD_SCHEMA_COMPAT if you want old schema codes */
+#define SLAPD_SCHEMA_NOT_COMPAT 1
+#endif
+
 @TOP@
 
 /* define this if needed to get reentrant functions */
diff --git a/include/portable.h.in b/include/portable.h.in
index fdf8b90b1b..335d22b90a 100644
--- a/include/portable.h.in
+++ b/include/portable.h.in
@@ -14,6 +14,11 @@
 
 /* end of preamble */
 
+#if !defined(SLAPD_SCHEMA_COMPAT) && !defined(SLAPD_SCHEMA_NOT_COMPAT)
+	/* define SLAPD_SCHEMA_COMPAT if you want old schema codes */
+#define SLAPD_SCHEMA_NOT_COMPAT 1
+#endif
+
 
 /* Define if on AIX 3.
    System headers sometimes define this.