PCbuild/python.vcxproj     | 1 +
 PCbuild/python3dll.vcxproj | 1 +
 PCbuild/pythoncore.vcxproj | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/PCbuild/python.vcxproj b/PCbuild/python.vcxproj
index 2094420a8d..7871e244b0 100644
--- a/PCbuild/python.vcxproj
+++ b/PCbuild/python.vcxproj
@@ -91,6 +91,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <PreprocessorDefinitions>Py_BUILD_CORE;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions Condition="'$(Configuration)|$(Platform)'=='Release'">/Ob3 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
diff --git a/PCbuild/python3dll.vcxproj b/PCbuild/python3dll.vcxproj
index ef344bed49..7f6394f942 100644
--- a/PCbuild/python3dll.vcxproj
+++ b/PCbuild/python3dll.vcxproj
@@ -97,6 +97,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions Condition="'$(Configuration)|$(Platform)'=='Release'">/Ob3 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <AdditionalDependencies>$(OutDir)$(TargetName)stub.lib</AdditionalDependencies>
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index 2625d0293d..af5ed2a38b 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -99,7 +99,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup>
     <ClCompile>
-      <AdditionalOptions>/Zm200  %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/Zm200  /Ob3 %(AdditionalOptions)</AdditionalOptions>
       <AdditionalIncludeDirectories>$(PySourcePath)Python;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories Condition="$(IncludeExternals)">$(zlibDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>_USRDLL;Py_BUILD_CORE;Py_BUILD_CORE_BUILTIN;Py_ENABLE_SHARED;MS_DLL_ID="$(SysWinVer)";%(PreprocessorDefinitions)</PreprocessorDefinitions>