diff --git a/src/emucore/tia/TIA.cxx b/src/emucore/tia/TIA.cxx
index a499f3351..a390487c5 100644
--- a/src/emucore/tia/TIA.cxx
+++ b/src/emucore/tia/TIA.cxx
@@ -151,6 +151,7 @@ void TIA::initialize()
   myXAtRenderingStart = 0;
 
   myShadowRegisters.fill(0);
+  for (auto reg: {HMP0, HMP1, HMM0, HMM1, HMBL}) myShadowRegisters[reg] = 0x80;
 
   myBackground.reset();
   myPlayfield.reset();