diff --git a/core/meta/inc/TIsAProxy.h b/core/meta/inc/TIsAProxy.h
index 5b43db54e9aefd91c3f4eac5e321a21d8a4785f9..5fabf20cd255765fe1dcfd8c51715e751e7d1151 100644
--- a/core/meta/inc/TIsAProxy.h
+++ b/core/meta/inc/TIsAProxy.h
@@ -37,13 +37,13 @@ private:
 
    const std::type_info     *fType;        //Actual typeid of the proxy
    TClass                   *fClass;       //Actual TClass
-   Char_t                    fSubTypes[72];//map of known sub-types
-   mutable Atomic_t<UInt_t>  fSubTypesReaders; //number of readers of fSubTypes
+   Atomic_t<void*>           fLasts[fgMaxLastSlot];   // points into fSubTypes map for last used values
+   Char_t                    fSubTypes[72];           //map of known sub-types
+   mutable Atomic_t<UInt_t>  fSubTypesReaders;        //number of readers of fSubTypes
    Atomic_t<Bool_t>          fSubTypesWriteLockTaken; //True if there is a writer
-   Bool_t                    fVirtual;     //Flag if class is virtual
-   Atomic_t<Bool_t>          fInit;        //Initialization flag
-   Atomic_t<void*>           fLasts[fgMaxLastSlot]; // points into fSubTypes map for last used values
-   Atomic_t<UChar_t>         fNextLastSlot;// Next slot in fLasts to use for update (ring buffer)
+   Atomic_t<UChar_t>         fNextLastSlot; // Next slot in fLasts to use for update (ring buffer)
+   Atomic_t<Bool_t>          fInit;         //Initialization flag
+   Bool_t                    fVirtual;      //Flag if class is virtual
 
    void* FindSubType(const std::type_info*) const;
    void* CacheSubType(const std::type_info*, TClass*);
diff --git a/core/meta/src/TIsAProxy.cxx b/core/meta/src/TIsAProxy.cxx
index 22e197ce53b89adf4584c77359ec59ce5630ecfe..eb9d4ac9b51881d5fc783ecee6631246208c8cae 100644
--- a/core/meta/src/TIsAProxy.cxx
+++ b/core/meta/src/TIsAProxy.cxx
@@ -48,7 +48,7 @@ namespace {
 TIsAProxy::TIsAProxy(const std::type_info& typ)
    : fType(&typ), fClass(nullptr),
      fSubTypesReaders(0), fSubTypesWriteLockTaken(kFALSE),
-     fVirtual(kFALSE), fInit(kFALSE)
+     fInit(kFALSE), fVirtual(kFALSE)
 {
    static_assert(sizeof(ClassMap_t)<=sizeof(fSubTypes), "ClassMap size is to large for array");