diff --git a/src/emucore/Thumbulator.cxx b/src/emucore/Thumbulator.cxx
index 36003ab17..554f4368b 100644
--- a/src/emucore/Thumbulator.cxx
+++ b/src/emucore/Thumbulator.cxx
@@ -355,6 +355,8 @@ bool Thumbulator::isProtected(uInt32 addr)
     case ConfigureFor::BUS:
       return  (addr < 0x06d8) && (addr > 0x0028);
   }
+
+  return false;
 }
 
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