diff --git a/hist/hist/inc/TH1.h b/hist/hist/inc/TH1.h
index 78291eb9183f8..c74a497ab318f 100644
--- a/hist/hist/inc/TH1.h
+++ b/hist/hist/inc/TH1.h
@@ -83,6 +83,17 @@ class TH1 : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
          kNeutral = 2,  ///< Adapt to the global flag
    };
 
+   /// Enumeration specifying inconsistencies between two histograms,
+   /// in increasing severity.
+   enum  EInconsistencyBits {
+         kFullyConsistent = 0,
+         kDifferentLabels = BIT(0),
+         kDifferentBinLimits = BIT(1),
+         kDifferentAxisLimits = BIT(2),
+         kDifferentNumberOfBins = BIT(3),
+         kDifferentDimensions = BIT(4)
+   };
+
    friend class TH1Merger;
 
 protected:
@@ -156,7 +167,6 @@ class TH1 : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
    static bool CheckBinLabels(const TAxis* a1, const TAxis* a2);
    static bool CheckEqualAxes(const TAxis* a1, const TAxis* a2);
    static bool CheckConsistentSubAxes(const TAxis *a1, Int_t firstBin1, Int_t lastBin1, const TAxis *a2, Int_t firstBin2=0, Int_t lastBin2=0);
-   static int CheckConsistency(const TH1* h1, const TH1* h2);
    int LoggedInconsistency(const char* name, const TH1* h1, const TH1* h2, bool useMerge=false) const;
 
 public:
@@ -199,6 +209,7 @@ class TH1 : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
    virtual Double_t Chi2Test(const TH1* h2, Option_t *option = "UU", Double_t *res = nullptr) const;
    virtual Double_t Chi2TestX(const TH1* h2, Double_t &chi2, Int_t &ndf, Int_t &igood,Option_t *option = "UU",  Double_t *res = nullptr) const;
    virtual Double_t Chisquare(TF1 * f1, Option_t *option = "") const;
+   static  Int_t    CheckConsistency(const TH1* h1, const TH1* h2);
    virtual void     ClearUnderflowAndOverflow();
    virtual Double_t ComputeIntegral(Bool_t onlyPositive = false);
            TObject* Clone(const char *newname = "") const override;
diff --git a/hist/hist/src/TH1.cxx b/hist/hist/src/TH1.cxx
index e9b2e79c44349..9ee730d01a5fb 100644
--- a/hist/hist/src/TH1.cxx
+++ b/hist/hist/src/TH1.cxx
@@ -594,21 +594,6 @@ extern void H1LeastSquareFit(Int_t n, Int_t m, Double_t *a);
 extern void H1LeastSquareLinearFit(Int_t ndata, Double_t &a0, Double_t &a1, Int_t &ifail);
 extern void H1LeastSquareSeqnd(Int_t n, Double_t *a, Int_t idim, Int_t &ifail, Int_t k, Double_t *b);
 
-namespace {
-
-/// Enumeration specifying inconsistencies between two histograms,
-/// in increasing severity.
-enum EInconsistencyBits {
-   kFullyConsistent = 0,
-   kDifferentLabels = BIT(0),
-   kDifferentBinLimits = BIT(1),
-   kDifferentAxisLimits = BIT(2),
-   kDifferentNumberOfBins = BIT(3),
-   kDifferentDimensions = BIT(4)
-};
-
-} // namespace
-
 ClassImp(TH1);
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1675,8 +1660,10 @@ bool TH1::CheckConsistentSubAxes(const TAxis *a1, Int_t firstBin1, Int_t lastBin
 
 ////////////////////////////////////////////////////////////////////////////////
 /// Check histogram compatibility.
+/// The returned integer is part of EInconsistencyBits
+/// The value 0 means that the histograms are compatible
 
-int TH1::CheckConsistency(const TH1* h1, const TH1* h2)
+Int_t TH1::CheckConsistency(const TH1* h1, const TH1* h2)
 {
    if (h1 == h2) return kFullyConsistent;