diff --git a/core/qa/CbmQaCanvas.h b/core/qa/CbmQaCanvas.h
index 2c2e7bdb89776027856763eedf9041c03f014a70..4bf3e3d33dab9205cd0f31c903ccac63ed75b8b4 100644
--- a/core/qa/CbmQaCanvas.h
+++ b/core/qa/CbmQaCanvas.h
@@ -52,7 +52,9 @@ class CbmQaCanvas : public TCanvas {
   {
     /// the static variable will be initialised at the first call;
     /// deleted at the application end (c++11)
-    static CbmQaCanvas dummy("CbmQaDummyCanvas", "CbmQaDummyCanvas", 1, 1);
+    /// Note: Sizes 1x1 to 3x3 pixels lead to crazy text size and an error under Debian 12
+    /// Note: Size 4x4 lead to a pad with size 0 and not statbox  under Debian 12
+    static CbmQaCanvas dummy("CbmQaDummyCanvas", "CbmQaDummyCanvas", 5, 5);
     return dummy;
   }