diff --git a/src/core/mormot.core.rtti.pas b/src/core/mormot.core.rtti.pas
index 8b8996e3b..b9717dd97 100644
--- a/src/core/mormot.core.rtti.pas
+++ b/src/core/mormot.core.rtti.pas
@@ -2631,7 +2631,8 @@   TRttiCustomList = class
     // - should be a reentrant lock, even if seldom called
     RegisterSafe: TOSLock;
     /// how many TRttiCustom instances have been registered for a given type
-    Counts: array[succ(low(TRttiKind)) .. high(TRttiKind)] of integer;
+    // - we include rkUnknown for safety
+    Counts: array[TRttiKind] of integer;
     /// initialize the RTTI list
     constructor Create;
     /// finalize the RTTI list
diff --git a/src/mormot.commit.inc b/src/mormot.commit.inc
index b0facb2e4..90348d115 100644
--- a/src/mormot.commit.inc
+++ b/src/mormot.commit.inc
@@ -1 +1 @@
-'2.1.6271'
+'2.1.6272'