diff --git a/src/sim65.vcxproj b/src/sim65.vcxproj
index 06f227d09..7a65f9384 100644
--- a/src/sim65.vcxproj
+++ b/src/sim65.vcxproj
@@ -48,7 +48,6 @@
       <PrecompiledHeader>
       </PrecompiledHeader>
       <WarningLevel>Level3</WarningLevel>
-      <Optimization>Disabled</Optimization>
       <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;_CONSOLE;_DEBUG</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>common</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
@@ -64,9 +63,6 @@
       <WarningLevel>Level3</WarningLevel>
       <PrecompiledHeader>
       </PrecompiledHeader>
-      <Optimization>MaxSpeed</Optimization>
-      <FunctionLevelLinking>true</FunctionLevelLinking>
-      <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;_CONSOLE;NDEBUG</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>common</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>