diff --git a/Makefile b/Makefile
index 771125958..23b5d6c2b 100644
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,7 @@
 
 srcdir      ?= .
 
+# -Wp,-D_GLIBCXX_ASSERTIONS
 DEFINES     := -DSDL_SUPPORT -D_GLIBCXX_USE_CXX11_ABI=1
 LDFLAGS     := -pthread
 INCLUDES    :=
diff --git a/src/debugger/CartDebug.hxx b/src/debugger/CartDebug.hxx
index 16ec41e16..da8f4b450 100644
--- a/src/debugger/CartDebug.hxx
+++ b/src/debugger/CartDebug.hxx
@@ -300,7 +300,7 @@ class CartDebug : public DebuggerSystem
     struct ReservedEquates {
       std::array<bool, 16>  TIARead;
       std::array<bool, 64>  TIAWrite;
-      std::array<bool, 24>  IOReadWrite;
+      std::array<bool, 32>  IOReadWrite;
       std::array<bool, 128> ZPRAM;
       AddrToLabel Label{};
       bool breakFound{false};
diff --git a/src/emucore/Cart.cxx b/src/emucore/Cart.cxx
index ed57ff42e..974b20e39 100644
--- a/src/emucore/Cart.cxx
+++ b/src/emucore/Cart.cxx
@@ -133,15 +133,13 @@ void Cartridge::pokeRAM(uInt8& dest, uInt16 address, uInt8 value)
 void Cartridge::createRomAccessArrays(size_t size)
 {
   myAccessSize = static_cast<uInt32>(size);
-#ifdef DEBUGGER_SUPPORT
+
+  // Always create ROM access base even if DEBUGGER_SUPPORT is disabled,
+  // since other parts of the code depend on it existing
   myRomAccessBase = make_unique<Device::AccessFlags[]>(size);
   std::fill_n(myRomAccessBase.get(), size, Device::ROW);
   myRomAccessCounter = make_unique<Device::AccessCounter[]>(size * 2);
   std::fill_n(myRomAccessCounter.get(), size * 2, 0);
-#else
-  myRomAccessBase = nullptr;
-  myRomAccessCounter = nullptr;
-#endif
 }
 
 #ifdef DEBUGGER_SUPPORT