diff --git a/src/debugger/CartDebug.hxx b/src/debugger/CartDebug.hxx
index dd3a800bb..1a34524be 100644
--- a/src/debugger/CartDebug.hxx
+++ b/src/debugger/CartDebug.hxx
@@ -298,10 +298,10 @@ class CartDebug : public DebuggerSystem
 
     // Information on equates used in the disassembly
     struct ReservedEquates {
-      std::array<bool, 16>  TIARead;
-      std::array<bool, 64>  TIAWrite;
-      std::array<bool, 32>  IOReadWrite;
-      std::array<bool, 128> ZPRAM;
+      std::array<bool, 16>  TIARead{false};
+      std::array<bool, 64>  TIAWrite{false};
+      std::array<bool, 32>  IOReadWrite{false};
+      std::array<bool, 128> ZPRAM{false};
       AddrToLabel Label{};
       bool breakFound{false};
     };