diff --git a/Lib/test/test_list.py b/Lib/test/test_list.py
--- a/Lib/test/test_list.py
+++ b/Lib/test/test_list.py
@@ -98,6 +98,14 @@
         d = pickle.dumps(it)
         self.assertEqual(self.type2test(it), self.type2test(reversed(data))[1:])
 
+    def test_no_comdat_folding(self):
+        # Issue 8847: In the PGO build, the MSVC linker's COMDAT folding
+        # optimization causes failures in code that relies on distinct
+        # function addresses.
+        class L(list): pass
+        with self.assertRaises(TypeError):
+            (3,) + L([1,2])
+
 def test_main(verbose=None):
     support.run_unittest(ListTest)
 
diff --git a/Lib/test/test_tuple.py b/Lib/test/test_tuple.py
--- a/Lib/test/test_tuple.py
+++ b/Lib/test/test_tuple.py
@@ -193,6 +193,14 @@
         d = pickle.dumps(it)
         self.assertEqual(self.type2test(it), self.type2test(reversed(data))[1:])
 
+    def test_no_comdat_folding(self):
+        # Issue 8847: In the PGO build, the MSVC linker's COMDAT folding
+        # optimization causes failures in code that relies on distinct
+        # function addresses.
+        class T(tuple): pass
+        with self.assertRaises(TypeError):
+            [3,] + T((1,2))
+
 def test_main():
     support.run_unittest(TupleTest)
 
diff --git a/PCbuild/pginstrument.props b/PCbuild/pginstrument.props
--- a/PCbuild/pginstrument.props
+++ b/PCbuild/pginstrument.props
@@ -24,7 +24,7 @@
     </ClCompile>
     <Link>
       <OptimizeReferences>true</OptimizeReferences>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <LinkTimeCodeGeneration>PGInstrument</LinkTimeCodeGeneration>
       <ProfileGuidedDatabase>$(SolutionDir)$(Platform)-pgi\$(TargetName).pgd</ProfileGuidedDatabase>
       <ImportLibrary>$(OutDirPGI)\$(TargetName).lib</ImportLibrary>
@@ -35,4 +35,4 @@
       <Value>$(OutDirPGI)</Value>
     </BuildMacro>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/PCbuild/pylauncher.vcxproj b/PCbuild/pylauncher.vcxproj
--- a/PCbuild/pylauncher.vcxproj
+++ b/PCbuild/pylauncher.vcxproj
@@ -199,7 +199,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -216,7 +216,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -233,7 +233,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -250,7 +250,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -267,7 +267,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -284,7 +284,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -308,4 +308,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/PCbuild/pywlauncher.vcxproj b/PCbuild/pywlauncher.vcxproj
--- a/PCbuild/pywlauncher.vcxproj
+++ b/PCbuild/pywlauncher.vcxproj
@@ -143,7 +143,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -160,7 +160,7 @@
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <EnableCOMDATFolding>false</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <AdditionalDependencies>version.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -199,4 +199,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>