diff --git a/Machines/Acorn/Archimedes/Archimedes.cpp b/Machines/Acorn/Archimedes/Archimedes.cpp
index c1132b069..2782bcec0 100644
--- a/Machines/Acorn/Archimedes/Archimedes.cpp
+++ b/Machines/Acorn/Archimedes/Archimedes.cpp
@@ -176,7 +176,7 @@ class ConcreteMachine:
 							executor_.bus.read(address, address, false);
 						}
 						while(true) {
-							uint8_t next;
+							uint8_t next = 0;
 							executor_.bus.read(address, next, false);
 							if(next < 0x20) break;
 							desc.push_back(static_cast<char>(next) & 0x7f);
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme
index 474fa352e..19b54b90e 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
@@ -62,7 +62,7 @@
       </Testables>
    </TestAction>
    <LaunchAction
-      buildConfiguration = "Debug"
+      buildConfiguration = "Release"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       enableASanStackUseAfterReturn = "YES"